War training someone you're not sure you can keep trained....What happens if it goes wild?
Well, can't be worse than pitting necromantic half of citizens against non-necromantic half, can it? n.n°
Ah, DF ‼science‼ projects....
Iirc swords are general-purpose weapons with 2 slash and 2 blunt attacks, but I see occasionally people building squads of them with specific squads present. Is it because of thematics, previous skill in the weapon or something I'm missing here?
Necromancer military acts a bit differently, hm. Not much need to worry about getting tired *gestures*, so optimizing them for initial/single target takedown seems like an untested idea.
As for taverns, I guess the main tricky thing would be to ensure that some are not overfilled while others go dry; perhaps using two-necro burrows/overlapping taverns to cater to each other - could also encourage marriages

Micromanagement heavy to set up, however.
As for the top layer of adamantine veins, I've certainly seen ones that are just 1 thick - so digging first up/down stair would release the hounds of hell. "Protecting" against mishaps is pretty trivial though with necromancers not needing to eat or drink to live, if one thinks Battlefailed could possibly die to some clowns.
Safe ways to enter the fortress....You mean, besides the airlock design sanctume set up?
Could also put a minecart to jump through a wall or fortification on the surface if they are unmanned, though a kea would probably steal it. Alternatively, two pressure plates followed by drophole of retracting bridge/hatch combo, second plate set to trigger on citizens, with meeting zone on second bridge. If quick-response trapavoid trap is desired, putting a nested bouncing minecart into only way in could work (dwarves get bonus to dodging carts, so they'll probably survive or explode).
Can't comment on FTW; have not tried it myself beyond accidental punctures for cavern flooding. Surface trenches to dodge into might work at smaller FPS cost, but it might be tricky to dig them without seeing the undead on surface....hold on, aren't we a submerged necromancer tower? I'm not sure flooding the world is really necessary for casualty-free ridding of undead.