Would people care if I made one?
Generally speaking on any <>, not much - but there's just not many people who would look. Look for the amount of interest your average mod/utility gathers; a whole handful of different people is probably above average. Do what you want; if others like it its a nice bonus.
I may not be the best judge for how popular this one would be, though - I'm not the type to easly change a graphics /tileset once I've decided on one for the fort.
And the best way of dealing with bitten people is to put them in a squad and lock them somewhere forever? Killing them once they transform? Can they ever be cured?
5) Use them as anti-syndrome warriors, as the transformation cures that (don't let them see each other transform, though).
If you can get them husked and swole, they're pretty much as powerful biologically as they possibly can be, though you'll find them rather more difficult to control them - and them dropping their gear on transformation is an unfortunately substantial malus to it.
6) Or maybe some kind of self automated item drop training as the transformation cures infections, as to get named armor/clothes (which no longer wear out).
Note that if you lock them away for item production, you should host all buildings on 1z pillars in a 2z room with ramps leading up (for workshops, this means deconstructing 8 edge floors). Buildingdestroyers can't destroy such buildings (this is sometimes used to make door FB-safe). The armor stand for military training can be walled after the room from it is designated.
I'm sorry for this barrage of dumb questions but...
If there's an attack going on somewhere in my fort and only not-so-good fighters are trying to fend the enemy off, is my best bet to create a "point" and send my squad there and hope that helps?
I would send my better soldiers to take care of it, assuming the better soldiers are good enough to deal with the threat safely.
If they would take some losses, it's balance-of-value decision: which are more valuable to you.
If you'd not mind losing the not-so-good fighters, then they'll still keep enemies busy for a bit. Use that time to build walls & locked door(lasts a day against building destroyers), or w/e as appropriate to stall them longer so you can setup whatever to take care of the enemy.