Just did a google search because I was curious. I found some info on XDA where people say you CAN go from verizon to Straight Talk,
It requires changing ESN from one donor ST phone to the verizon one, which is not just a TOS violation but is also borderline illegal/fraudulent. Nobody on this forum will provide any information on how to do this and I dont think most people would consider a phone "compatible" on another provider if it involves ESN tampering to get it there.
Either way, looks like you are getting your answers so have fun and good luck.
My inexpensive low end android phone does everything I have asked it to do... why spend hundreds on a new flashy one?