For the Divine Spellcaster I would limit it so that the undead casting caps at like 2nd level spells. Spell Stiched is a REALLY strong and expensive template. Being able to have all your undead cast 1st level spells is still really strong. I mean once again now max HD cap in human skeletons all casting magic missile. I personally would remove it from the secrets list and add it to Corpse Enchancing. Because its a really expensive template and getting it for free is kinda strong. They fixed it regularly from spawning undead by making it really expensive .
Ya curse of the necromancer needs some kind of definition on what the curse is.
Ya good idea for the fix for Enhanced Anatomy, just something to prevent spam like that.
And thanks for the compliment, I like to look at things from a loophole perspective. Also I don't practice a lot but necromancy and undead are my favorite to work with so with reading so many tricks with undead some just stuck. .