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"Duff himself said that 'This code forms some sort of argument in that debate, but I'm not sure whether it's for or against.'[5]"  (From the Wikipedia article on Duff's Device.)

Maybe not.  Ambiguity, like evil, can never be completely extirpated.

Do you think that "We get the legislature that we deserve"?

Ah, you've been spared my tirades on the Matter of Comma.  I'll not burden you now but to say that I agree with Le Guin's declared position.  All the hooey is just the machinery and minutia.  But the gestalt emerges from the detail like the forest emerging from the trees.

I better go before I start to play Zen.  And embarrass myself.

Need?  What is the criterion of need?  Some stylebook?  Or helping the reader find the most important breaks in the grammar flow?  If the latter, I would place one before 'observing'.  The other grammar breaks lie within the sections that are separated by this comma.

Any reason for 'observing' instead of 'watching'?  Is 'early evening' needed, given that you tell us of the color and the setting sun?

In other words, around both in the same direction.

What if the orbit was irregular, several orbits around Sun 1, then a swing to Sun 2 for an uncertain number of orbits, then back to Sun 1?  If the two suns don't have a mutual circular orbit, you could postulate strange-attractor behaviour.

Kdot hit the orbital mechanics question, though I suspect it's even a bit more interesting than that.  (Ooh!  It is!  Look up Lissajous Orbit and Halo Orbit on Wikipedia.  If you can use an orbit around a Lagrange point, they might work for you.  Oh,yes: Look up Lagrangian Point, too.)  But first I'd like to talk about your planet's thermal equilibrium.  I'm going to belabor some basic points so you can follow the question a bit more deeply.

Heat is transferred though 'empty' space by radiation--light, that is, and mostly infrared for a habitable planet.  When we on the surface face the sun (daytime) we soak up its heat.  When we face the deep dark of space (nighttime) we radiate heat out into that abysssal void.  The very delicate balance of heat absorbed and heat released creates the narrow band of temperature in which life is possible on most of our planet.  And they most important limits are the melting/freezing point of water and the temperatures at which proteins start to denature.  (Forget about silicon-based life.  Bonds between silicon atoms are too damn strong.  No adhesive will bond to silicone.  Not even silicone adhesive.)

The next thing to understand is the inverse-square law.  This follows from a simple geometric reality: The surface area of  sphere increases in proportion to the square of the sphere's radius.  If an energy source (like a sun) is radiating in all directions from the center of a hollow sphere, the total energy released to the sphere is the same no matter the size of the sphere.  But the energy that hits a patch of fixed area is a fraction of the total, and the fraction is the fixed area divided by the surface area of the sphere.  Since that area goes as the square of the sphere's radius, the energy available to that patch of fixed area goes as the inverse of the square of the radius.  And since the intensity of the energy flow (ie., the 'flux') is measured as energy per unit area, the intensity of radiation from your sun falls off as the square of the distance from the sun.

A nearly circular orbit will provide a nearly constant luminous intensity to the planet.  A highly elliptical orbit--or a figure-eight orbit--will create immense swings in heating and cooling.  Moreover, the planet's velocity will be highest at its nearest approach to the sun, where its gravitational potential energy is the lowest.  The sum of potential energy and kinetic energy of motion will be constant (neglecting relativistic and tidal losses over cosmic ages).  Note also that kinetic energy goes as the square of the speed.  In a noticeably elliptical orbit, your planet will race through a hot zone in one short season and mosey languidly through the heat-absorbing blackness of the void for the opposite, much longer season.  Life as we know it on earth is possible because earth's orbit is very nearly circular.

(A digression on ellipses: In an elliptical orbit, a light body travels in an ellipse around a much heavier body--and this isn't quite right; see below--with the heavy body at one of the two focus points of the ellipse.  The focus points lie on the major axis of the ellipse, and every point on the ellipse meets two constraints.  First, all points are in one plane.  Second, for each point the sum of the distances from the point to the two fociii is constant.)

Next question: When is a square foot not a square foot?  (If you are too square for feet, substitute 'meter'.  It's just a constant factor.)  Well ...

Imagine you are standing on earth, on a sunny day.  You hold in your hands a sheet of material one foot square, and you hold that sheet perpendicular to the sun's rays.  It receives one square foot of solar radiation.

Then you turn that sheet about an axis in the plane of the sheet, so that the plane of the sheet is no longer perpendicular to the sun's rays, but instead lies at an angle of 30 degrees from them.  Along the axis on which you rotated the sheet, the sheet still shadows the same distance it shadowed before, but along an axis perpendicular to the rotation axis (and perpendicular to the sun's rays) the shadow is shortened by half.  Your square foot of sheet is absorbing only half a square foot's worth of solar radiation because it is canted to 'look llike' half a square foot 'to the sun'.

You may be noticing a theme here Geometry Rules!  As always and ever it has.

Imagine now that you are standing on the earth's equator at high noon (local high noon) at one of the equinoxes.  You hold your foot-square sheet parallel to the surface of the earth (ie., perpendicular to a plumb line).  It receives one square foot worth of solar radiation.  (We'll neglect losses to the atmosphere to keep the problem simple.)  Imagine next that you are standing in Cairo, at local high noon, on the equinox.  Cairo is at thirty degrees north latitude, so your plumb line lies thirty degrees away from the line of solar radiation.  Your foot-square sheet now looks like root-three-over-two feet (about 0.87  square feet) to the sun.

Move to Montreal, at 45 degrees north latitude, local high noon on the equinox.  Your 'horizontal' square foot sheet presents only root-two-over-two square feet to the sun.  And when you set your square foot up in Helsinki at local high noon on the equinox at sixty degrees north latitude, you'll be presenting only half a square foot to the ever-generous sun and its radiation.

Belabor, belabor, belabor ...

Okay, we're getting to seasons and tilt of the planet's rotational axis.  I'm assuming that your planet will have at least some of that.  You could make it weird and have the axis in the plane of the orbit, but that means that during the 'year' there will be times when one hemisphere is in continual hot day and the other is in frigid, sky-void-cold night.  (Speaking of planetary rotation, will your planet have a magnetic field?  Very good for keeping particle radiation away from the surface.)

You're going to have to figure out how much energy is coming off each sun, and how that relates to stellar mass and age.  (See Stellar Evolution on Wikipedia.)  Small, even very small, changes will have major consequences over time.

Remember when you learned that the earth orbits the sun?  Well, that's a lie.  The earth orbits the center of mass of the solar system, and because Jupiter is so massive, it pulls that center of mass outside the sun's corona.  The other planets can increase or decrease this effect, depending on where they are relative to Jupiter.  This means that earth is sometimes closer to the sun than at other times, depending on the position of Jupiter, and that is one reason why we have long-term cycles in climate.  (Solar sunspot cycles are another reason.)

The three-body problem is the general case, and determines if the specific case is feasible.

The case where the planet's orbital motion is at right angles to the suns' plane opens up possibilities that may not exist in single-planar motion.  I don't think the changing velocities would actually allow a truly planar orbit, even in a rotating plane, but it might allow a solution that would otherwise be infeasible.  But in any case, gravitational drag is going to affect the planet's diurnal rotation, perhaps even in geologic ages.

You've got an interesting physics problem.  Interesting in Physics means "damned hard, maybe insoluble with present math tools, maybe chaotic and thus truly insoluble (but look up 'strange attractors' online)".

Are the suns symmetrical?  If so, they revolve together about a point nearly centered between them.  If one is more massive,  the center of revolution will be nearer one than the other, maybe even within the larger one's outer corona.  Over astronomical ages, they will fall towards each other due to energy loss to gravity waves (General Relativity).  In some cases, long geological ages may approach short astronomical ages.  Whether this has affected biological evolution is a call for you to make.

The deeper the planet is within one sun's gravity well, the faster it must be moving to  avoid being pulled into that sun.

I could write between one and five thousand words on this, and never even get near writing solutions.  And since I've never studied orbital mechanics, it would take me a day or to a week just to get the simultaneous differential equations right, and days to weeks to find approaches to the solution.  I'll write the words if you like, but setting me on the math task would be either folly or desperation, and probably Sisyphusian (and cruel).

Isaac Asimov wrote a famous story, Nightfall, a generation or so ago.  It was before knowledge of mathematical chaos made it out of research papers and hand-waves a lot away, but you might get some sense of the problems from it.

If the prologue constitutes an interesting story itself, you should definitely keep it.

Everyone struggles.
Neither side realizes what's at stake for the other side.
The conversations themselves would not push the lover to suicide, but they lay the path.  Something else, something of (apparently) pure chance gives that final push.  Or perhaps we see him draw a false conclusion--after the fact--from something that Romano said, perhaps inspired by something else.  If that something else has a back-link to the satanic cardinal, so much the better.
Does Romano want to believe the cardinal?  Will he be caught between what he'd like to believe and what he really believes?

I'll repeat my recommendation for =The Secrets of Story= by Matt Bird.

Congratulations, AGAIN!