No it won't wreck your computer. 0% chance of that. I'm a big pcsx2 user and a member of ngemu, and through the thousands of posts and threads I've read and tutorials I've read an my understanding of computers theres no chance it could damage your computer. I assume your talking about maybe damaging windows criticla files forcing you to have to reinstall windows, that won't happen as neither pcsx2 or any ps2 game modify any of those files. And damaging hardware is pretty much impossible with any program(with the exception of those that overclock yourcpu, gpu or increase voltage)
PCSX2 and its plug-in are being updated almost weekly. If you use the latest gsdx9 11.0 graphics plug-in (which is only available on the forums) alot of games work properly now, and are much faster than before. Configuring the emulator and getting it to play isn't to difficult (took me 30minutes before I was playing my first game).
Go to www.pcsx2.net and see if it is on the compatability list.