I didn't really test this one in that regard, because I had no previous unmodded Vampire Count saves, so to answer as best I can- I'd be cautious. I don't imagine it'd cause a save to completely crash if removed mid-playthrough. The unit and ancillary changes are 100% safe, but funky things happens when you start messing with buildings and new effects. One time I made a Tomb King mod to adjust unit capacity and nothing else, and adding that midway through made my displayed income go blank.

If it were me, I'd treat this as a "no", but that's because I generally am conservative and paranoid about save data.

Unfortunately, I've got a bit going on in my life right now and I probably won't come back to modding anything until my mind's straight.

is save game compatible?

oh yeah?

Not going to lie, I came to a similar conclusion. I thought of doing further economic tinkering, but I kept worrying that it would just mean more free skeleton spam. And I didn't just want stacking cost cuts for everything so you could use more monsters and elites. I thought of doing something with grave sites, but I'm not an amazing script writer, and that also goes against my idea of these mods staying as close to vanilla+ as possible.

sounds like a great rebalance, i still think the faction needs a mechanics update but i'll be trying out your mod soon since they are my fav faction and i've been itching for them to be more competitive