I finally got mine to work. Just letting you guys know.
First step I found that was making any progress was to call cricket and complain that I wasn't getting any pictures. They reset my account. Then I used all the settings that they list in other threads. Froze all the programs that kept redoing the Verizon settings and entered APN settings but I didn't change the numbers to 310 and 016 or whatever they maybe. The proxy settings were very important. Then I removed the sim card because it kept telling me service denial and now I can send and receive MMS.
Its a little more involved but I wanted to let you know it can be done and I'm even using the stock messages app.
I will come back later and write it up better if there is any interest. I'm just not sure if anyone still uses the Rezound anymore. I think everyone got the Galaxy S3 by now.