Hi there,
Here are some suggestions for how I might handle those in my games. YMMV:
Regarding disguise attempts. If you mean a person trying to disguise themselves using normal means, I would suggest Guile as the skill to apply. However, I think it depends on how the character is trying to disguise themselves, in which case agility could work (if the disguise represents how well the character can keep their identifying features hidden). Characters just trying to hide in plain sight with a well chosen outfit and total confidence could be a will check (representing how brazen confidence might distract from any flaws in the disguise). For a quick, simple test, describing how the disguise is being attempted could justify applying almost any skills. Even disguising yourself as an animal could be attempted with a wilderness check.
If it is more elaborate disguise, especially for multiple characters, it could require a combination of a lore check to know what features a good disguise should have, especially if trying to look like a specific person or faction member (clothes, items, makeup, hair, equipment, etc), then acquiring the materials my be needed followed by a crafting check to make the disguise. Then a check to to apply the disguise, and a guile check to pull off the deception in encounters. For an important moment of an adventure when the success of a quest depends on the deception it could be worth spending the time roleplaying to that extent.
For raising dead, that might require some Referee house rules. Permanent magic effects tend to only come from Miracles which require a permanent loss of 2 Health. Other ways could come from creative use of alchemy (with some potent and hard to find ingredients, probably unsavoury ones), or an artefact of some kind. Either of which might grant the ability to raise dead for extended periods without recasting empowered Necromancy.