1. Yes. I use this http://www.rivbike.com/product-p/m5.htm. They call it the "german mirror"; it's made by D + D Oberlauda. Neither of my bikes can use a bar-end mirror; one has bar-end shifters and the other has rubber grips.

The "german mirror" can be mounted anywhere on a handlebar, on any handlebar, and even on the fork, rack, or frame. It has a huge mirror that shows a lot of what's behind you. It looks super dorky, like any mirror.

I don't like helmet mirrors because they're too small, get whacked out of alignment too easily, and I couldn't find one that doesn't vibrate itself out of alignment after a couple miles. I don't wear glasses and change out my sunglasses often, so glasses-mounted doesn't work for me either.

2. An arm-mounted mirror just sounds really sweaty to me. Gross. Plus it doesn't look like it's really in the field of view without turning your head.