The amp and the subs will be just fine if you do everything properly. Most important: DO NOT TURN THE VOLUME UP BECAUSE THE SUBS AREN'T LOUD ENOUGH. I can't stress that enough, I see toooo many stupid people doing that and they get ultra clippage and it just sounds terrible and it is burning up their subs. Just make sure your gain is set properly and don't try to make up for lack of bass by cranking it and you will be fine for now. But you def need to look into getting a more powerful amp.
It's not about ruining the sub (100w into a 600w RMS sub? I doubt that the DC signals from clipping would be enough to blow it, maybe Glasswolf could settle that). It's about the sound quality, he or she needs to get a better amp.