Lets say there isnt much healing required, do i still get the exp or will i only get exp based on a certain formula in relation to how much i heal.

It is directly related to how much you heal, as I understand. What I do with my guardian and magician is just attack with whatever weapon I'm using when I don't need to heal, and then I'll get experience

It's based on how many "actions" you take, where an action is either attacking or healing. You won't gain much experience only healing, of course, so as stated above, you should attack while not healing.

There's no known formula or anything, just the more actions, the better.

Oh, ok. So even if my melee attack is doing only some 10 odd damage, its going to be sufficient?

Yup you will still get exp even though your dmg isin't good.

Alright, thanks.