I don't know Android, but I have no reason to believe it functions differently than the iOS app (but look for things if you don't see what I'm talking about...).
Yes, you can hook it up to a PA - why shouldn't you be able to? Just buy the right connectors, the sounds are good.
"looping" is a specific function, not for gigs. What you want is to repeat CHORUSES of songs, and that setting is right on the player screen (number between repeats).
Hope this helps...