Well, there are quite a few people who do shoot plain lead out of Glock handguns. I do in 10mm. I'm pretty sure some people do in 9mm also. I don't have first hand experience on this because there are 9mm handguns that I like a lot better than a Glock. With 10mm though, I didn't have that many choices in that price range.
As far as the other questions that you asked ... Well, just keep reading...