Mo/Rt questions

I just got factions and I am thinking of trying out the ritualist class. Being a total noob with the class I am not sure how their skills interact. Anyway onto the questions

Can I cast monk spells directly on the spirits themselves to heal them and keep them alive longer?

If I can are there any restrictions on what spells can be cast on the spirits?

And if I can't directly cast on them would the heal area spells still heal the spirits since it targets all creatures in the area?

It seems like I should be able to cast spells on the spirits because in some situations it would make more sense to keep a key spirit alive for the whole parties sake rather than casting a single heal on 1 party member. But anyway I would appreciate it if anyone can answer these questions.