1) Yes, it should fit any mag that TM or based off the TM design. It *may* require some filing down or taping to make it thicker but it will fit.
2) As long as you want it to. Really I don't know but it probably will last a while before anything breaks and you have to repair it. It WILL break down though (as everything does) however it's not likely it will break down within the first few uses like some of the cheaper clones out there.
All you have to do is just not mess around with it. Play with it completely stock for a while (which it sounds like you're going to do) and once you get some experience and know what you want to achieve it will be easier to upgrade. I've heard once you crack open the gun even if you don't change anything you've reduced the reliability. I'm not sure how true that is but TBH I liken airsoft more to "magic" and less to actual engineering applications of why things work the way they do. It's messed up, just like Digital Design.... (For some reason my circuits seem to work by "magic" when I'm actually building it and it's sometimes totally different from the CAD design that I made).
ಠ_ಠLess QQ more Pew Pew
READY TO >> RACE