What year is this RX model? Model number? The only ones I can think of off the top of my head were the Korean made 22 fret versions of the RT series made in '93. A picture would help with an accurate price analysis.
1) totally subjective, depends on the setup and your own preferences. Almost any guitar can play decently if set up properly.
2) Probably, especally if it's a solid body, and not some cheap laminate (plywood) body. IMHO, vintage style trems are the best for beginners, to allow for tuning changes necessary for learning songs.
3) Hard to tell without seeing it. You can pickup used RG5xxs for around $250, so go from there...