1. Only necromancers. It happens during recovering, regrouping, and preparing, and necromancy is the skill that lets you do it.
2. Useless. There are probably magical ways to get armor against ghosts, but your normal armor doesn't help.
3. This is one way, yes!
4. Or.
Actually, how can I explain this.
So here's a mourning ghost. It's making psychic attacks upon you and you're like, this is irritating, what can I do? Answer:
Do you want to drive it away forever through the jasminite gates? In that case, you have to use necromancy to contend with it, to inflict the 3 requisite harm.
Do you want to bind it instead? Then you have more options:
1. Do you have something to offer it, an exchange of services to propose? Do!
2. Do you hold something over it, its binding name or some dread threat? Apply it!
3. Otherwise, you can use necromancy to inflict 3 harm. NOW you're holding something over it: now it must agree to serve you or you can send it through the jasminite gates against its will.
Does that make sense?
-Vincent