Welding a crack would likely completely ruin a cymbal (I've never tried it, but I shudder to think at how that would ruin the chemical composition of the metals).
The best way to deal with a crack - drill a hole at the end of the crack. This method provides a "clean" edge, to prevent the crack from traveling further up the cymbal.
JustaBassist, everyone can have an opinion. ZBT cymbals are certainly entry level and candidly, I would not play choose to play ZBT cymbals (although if I was a young kid, just stating out I would play them - better than no cymbals). However, if a drummer has "pieces flying everywhere" he/she is doing something wrong.
If you were breaking strings consitantly, would you perhaps explore the possibility that your technique needed some corection? Or would you simply blame the guitar? If it comtinued to happen with a 2nd and 3rd guitar would you then contemplate technique, or would you blame all guitars???