Sorry for taking so long to respond to this! I think this is a great idea and a great conversation. I have a number of thoughts and ideas on the questions you posed above. I think you did an AWESOME job of identifying the relevant questions. Here's what I think for the 8 you mentioned:
1) The rewards are tricky. I know some people have had problems actually not being able to finish products and I don't think we want to disappoint anyone like that. SO... I think we should shy away from providing a complete, assembled ROV (although maybe I'm wrong). My thinking is that the rewards should correspond to the goals of the project, which, in my eyes, is to get more awesome developers and hackers working on the project. I think one of the rewards should definitely be the shell of OpenROV to allow for developers to put any electronics/motor configuration they want.
2) See above, getting the OpenROV in the hands of more people. More contribution, faster development, more awesomeness!
3) We've had a number of conversations with groups who want to use the robot - conservation groups, explorers, tinkerers, and educators. I think it's important to cater to all those groups.
4) As Eric has said, the benefit of "marrying" the ROV to Android is that it's now connected to a technology that's growing at a very fast rate, with lots of contributing developers. Lego Mindstorms would rock, though!
5) Awesome idea! Who do you have in mind?
6) Another awesome idea.
7) Have tried reaching out to a few with little luck. If anyone knows anyone...
8) Again, awesome idea. Competition inspires action.
More thoughts to come...