Hi David,
1,2) The user profile is a templated view of the core user data, you do not edit fields in it (there was no point in reinventing the wheel as the core already does this). You can read more about it here, and see a live example on PokerDIY here. So yes, you can add/edit any fields you want and adjust the template accordingly.
3) I have not used this module, but Cutopia know nothing about Smart-Thinker, so I doubt it. Have you seen the user directory (part of the UserProfile module)
4) Yes, there is only one template per module instance.
5) Yes, it integrates with Ventrian Private Messages. Try it on PokerDIY to see if it does what you want.
6), Yes, you can see all the prices and options here.
Please download the fully functional trial to see if it meets your needs.