Not recommended at all! My wife is the same size, and had a 56cm frame (bike shop sold that to her). Se had neck pain and could not handle the bike well. Get the right bike shop to do a propper fit before you buy.
Agree with CraigZa. It is probably the rim. It could also be the spring rate of the shock that gives it that feeling. I have a Rock Shox Revelation (which is a longer travel Reba) and it is very stiff.
No, not compatible. What you can do is put an eight speed casset on a seven speed free wheel body. Back when shimano went from 7 to 8 spd, they made the chain narrower to have the same total width on 8 spd as the 7 spd.
