1) With the lastest FMS 8.3 it's almost as good as Pre-flight but the important thing to note that ONLY FMS is free, Pre-flight isn't. In FMS you can control all four channels (aileron, elevator, throttle, rudder) but in the download version of Pfre-flight you can control only two - you have to pay to get the interface that allows all channels to be conrtolled in Pre-flight. Otherwise you have to use the keyboard and there's no way you can learn anything flying an R/C sim without at least a joystick (and, ebtter still, an interface that allows your real R/C transmitter to be used)

2) Neither is THAT close to reality (you have to pay for RFG2, AFP or XTR to get "reality") but they're good enough for learning basic controls. Once you have the controls mastered then add some wind to the simulation which will add to the realism

3) As I say, Reflex XTR, AeroflyPro or RealFlight G2. Most who've used more than one seem to agree that AFP/XTR are better than RFG2 but between AFP and XTR it's a close call - both have strengths and weaknesses.

Yup practice it is but do youself a favour and at least pay the $20 to get an FMS interface cable from Ebay to attach your Tx to your PC

Cliff