In my experience, flashing ROMs varies with each model, (I had a XDA II, XDA Mini S, XDA Orbit, HTC Diamond over the years) and I never bricked any of them. I suppose if you follow the guides on the xda-developers forum you should be ok.
I should point out that I haven't been on those boards for a while due to the credit crunch.
I don't have a windows mobile phone anymore, and I'm stuck with this piece of crap: