Ring Height
#3

I did a writeup a while back on measuring scope ring height specifically for this question. Take a look, it will help you understand how to do it exactly.
My instinct is to go with medium, but you'll want to measure to be sure.
My instinct is to go with medium, but you'll want to measure to be sure.
#5

I just put a 3.5-10x42 on a mountain rifle with Leupold std dovetail rings, I used low on mine. Can't say for sure if it will work on yours. I would think med would work for sure, and the low's may.