experience for spirits

[lilmoon]

hi all,

questions:
1) how much experience does every spirit of rage get for each stuff they do? do you have a list? the more the cost of it the more experience?

2) why if I use twice for example soul drain, I get experience only once?

3) I improved my soul drain up to 45 rage... I hope I will get a chance to lower the cost sometime, will I

tnx