I think FMS is okay.. Probably the best thing it teaches you is which way to move the sticks when the plane is coming towards you, since the plane is orientated different than it is when the plane is moving away from you. It sounds simple, but this is a huge hurtle for newbies of planes.

If you want to get a much better sim, get the realflight.. The physics in it are such that I believe it is much much more realistic than FMS, and much closer to actual RC flying. I saved some $$$ by buying the older Realflight 2 when Realflight 3 came out.. You could try the same if you don't like the price of it, but I gotta tell you, I've saved WAY more $$$ than if I woulda just bought planes and wrecked them.

My dad bought Realflight as well, and learned to fly using it. I think this is a real solid way to go..

As for your crashes on your Firebird, I have a couple of ideas.. 1st, center of gravity is a crucial adjustment.. It must balance at the proper point on the wing, and that point should be listed in the instructions.. If your plane is tail heavy, you'll never get it to be controllable- if it was outta balance, adjust it, and you'll be starting with a level playing field!
2nd, after your first big crash that bent and creased things, your controls could have then been way outta wack! And also check and make sure your controls aren't reversed as far as the turning goes.. That can happen to even the pros- and many planes have been lost to that!