Your character will generally be able to heal major wounds, but if someone's suffered fatal damage you won't really be able to bring them back from that, and some wounds may be permanent despite your best effort. Basically, anything that COULD conceivably be healed on its own given the time and medical equipment you can heal a lot faster, but as with major injuries even with the magic permanent damage may still be there no matter what if it's bad enough.

And yes, undead, vampires, and other spirits exist in this setting and would be vulnerable to such magics. They're most likely to show up in ruins or when fighting against the Empire's Necromancer corps since the Empire loves reanimating bodies for simple menial labor.