I'd say there's nothing wrong with a small amp for a mandolin if you use it right, and I don't know anyone I've ever played with who'd disagree with that. But some people do get their knickers in a twist over the strangest things, so maybe yo could check against that with the people yo play with.

"Rhythym chop" - what's that mean and how do you differentiate it from a strum, Willie-O?