That would be important if our officer's were doing the math with pencil and paper. Luckily they will have computers.The trajectories for all of those scenarios, and more, can be calculated in seconds with modern computers and modern commercially available software, like this one: http://www.agi.com/products/by-product-type/applications/stk/stk-for-space-missions/
True, and how long has it taken to put all that together.
It wasn't in a few hours. The data and programs took a long time to generate.
And even with modern computers, the 'fudge factor' still exists. If we could calculate these things exactly, we wouldn't still be guessing most asteroids' orbits. We would also be able to fire two part 'penetrators' at comets and asteroids from Earth orbit. Trust me, we still need to make a LOT of course corrections on the way to shoot something as big as an asteroid that we have been watching for years.
As for breaking strengths of material, I actually am an engineer and physicist so I have a pretty good idea on this one. If we are assuming a projectile leaving a railgun at perhaps 10km/s (is this acceptable?), and assuming it is shot from a ship with a diameter of 50m with the whole length of the ship used for the driver, it will leave the barrel in .01 seconds after first acceleration assuming even acceleration of the projectile. One G is an acceleration of appox 10m/s/s. The projectile from this gun just withstood 1 MILLION G's of acceleration stress.
Google the load strength of any material known per mass, and see if it will withstand 1,000,000 times its mass in load.... You will find that NOTHING comes remotely close. Let alone a piece of machinery with the fine calibration to make in course adjustments. Every known material in this gun would be reduced to its component atoms (most likely). Some dense materials might reach degenerate matter levels of compaction if your railgun had a high enough muzzle velocity. (The thought of shooting unstable degenerate matter at something so that it detonates might be fun though...).
On the thought of nukes suffering sympathetic detonation, not likely at all. The only case I might see was if a ship had one prepped for launch and for some insane reason had the thing armed in the launcher - and then the vessel was hit. Otherwise, not going to happen. If it was unstable enough to detonate under inadvertent acceleration/heating/etc, I wouldn't want it on MY ship...
And I don't know if this would go in a suggestions thread or here, (this is the only group of threads I have spent much time on game-wise), but I think most all of the missiles should have the option to default to a kinetic kill if you choose not to arm them. A several ton intact nuclear/conventional/shapnel warhead hitting a ship at km/s velocities isn't going to look a lot different than a big old chunk of metal doing the same thing. Using a nuke this way might be an expensive waste, but might be attractive if you have a bunch of small ships near the target - or perhaps your colony on a moon with no atmosphere to protect them - or an orbital habitat. Just a thought.