1) There are some ways to heal afflictions like a special unique item (the chalice), a global enchantment or by some national commanders like the Arcoscephale Priestess. Just waiting helps nothing.
2) no advantage, its just like doing it with a level 4 magic skill.
3) yes, its possible
4) nope
A nice site with some infos are this one
http://www.freewebs.com/dominions2/
Its mainly dom2 but it helps for dom3 too.
Dom3 Wiki:
http://strategywiki.org/wiki/Dominions_3:_The_Awakening