Unfortunatly, I don't know much in flashing phones to a different provider...however, if you've gotten this far, have you tested activating it and doing a PRL update via Cricket's Network? Not sure what the number is...
1. If you needed that to activate then you are correct, however, after you are able to flash the phone, you should contact Cricket via their number and see if you are able to update the PRL similar to Metro's method of dialing Activation and pressing 5.
2. I'm not familiar with Cricket so I can't be sure if that's right or wrong. However, I can defiantly say that there shouldn't be a problem activating it with Cricket if the setup was done correctly. Just don't call Metro. XD
Again, not familiar.
3. Normally, phones are not sold unlocked, however if yours is, then you shouldn't need to use the workshop, unless there's something preventing you from gaining access to Cricket.
Sorry I'm not much help, Cricket doesn't service my area so never had experience with it, but it sounds right from what you did. Is the phone working might I ask?