<< -1- Can i do a transition from PVC to PEX ? >>
Probably , if you have the right combination of fittings. Why not do Pex back
to the source?
<< -2- Is this a bad idea ? >>
Pex is considered a superior product to PVC.
<< -3- Anything else you can tell me would be helpful. >>
Crimping fittings may be tricky. Be sure you have all the right tools and some
practice material to get a nice job. Good luck.