1) any resources from any RM that you have purchased can be edited and used in any RM that you have purchased, but ONLY in the RPG-Makers, they are forbidden to be used in any other engine unless you purchased the non-RM variant of the pack. For some packs, that non-RM licence is available on our sister size (but more expensive), for RTP and a lot of the other packs the non-RM licence doesn't exist.
2) you can sell any game you made with any of the RMs you purchased (not with the trials), but you're responsible for handling the taxes and laws of your country