Before they changed the sprite, it was very selfish. The only spells they had were sprite, pixies, and guiding light spells. They healed themselves more then the people who needed it. I wish they left the guiding light on.
I doubt it. The sprite is there to help keep you alive so you can focus on attacks.
If you want more minions, try Myth. They have several.
It's funny, I personally believe the Storm minion does more healing than the life minion. The storm minion casts balance shields, taunt and sprite all the time (the target is random). The life minion likes to cast Leprechaun a lot! I'm not complaining since a life wizard is already doing most of the healing, it seems they would need a little boost in attacks. I just find it a little amusing.