EDIT: third question: Can you interact multiple times in one turn? IE can you recruit and buy healing and buy an advanced action all in one turn at a Monestary? Or can you buy two spells or recruit twice at a mage tower? Etc.
Third question: you can do multiple things when interacting in one turn, but you only interact once. To interact, generate influence points then spend them however you like - in one interaction you could generate (say) 7+2+6=15 influence points to recruit, heal, and get an advanced action.