It wouldn't take "fala". I think this should be accepted too.
Can I use 'bastante' ?
Yes, but we'd probably say: "meu amigo diz que ele te ama bastante"
Why can't it be "... ele ama você muito" instead of "... ele ama muito você"? It kind of sounded natural to me, but I don't really know if it does in proper Portuguese. I had it marked as wrong.
That's a different construction. In Portuguese it would sound awkward.
Can you say "quer" instead of "ama" (as in Spanish)
It seems possessive. It does not sound good.
It sounds more like "want" then, rather than "like"?
"Te" has not been introduced yet. Bad exercise at this point.