If you are staying on site, then enjoy on site, take Disney transportation. Make ADRs and eat at Disney restaurants. Don't try to do too many meals with the group. DO GO to Extra Magic Hours and take some day time to lounge by the pool or grab a hammock. That time of year the parks are not packed so the EMH should be nice. The others can't come, but next time they will consider on site too!
As for CBR no matter where you stay you will have to walk, its a resort, not a hotel per se, so things are spread out and in different bldgs. We were in Martinique #22, very convenient, but still a pleasant stroll, 5 mins or less.
I really liked the food court there we had breakfast platters, pizza, snacks and veggie burger there. Pleasant, informed staff, clean and lots of choices. There are so many good places to eat at Disney, I'd probably go elsewhere vs Shutters. We did not eat there, but Coral Reef in Epcot was good. Of the Buffets Boma at the Animal Kingdom Lodge (drive there since you have the car) and Chef Mickey's (loud character meal) at the Contemporary (take bus to MK then walk back to the Contemporary) are places we enjoyed and will return to on our next trip.
We loved the convenience of the Dining Plan, but it may take more convincing if you plan to eat off site with the friends. My vote will be to eat those group meals on site with the friends, making sure your check is separate. Just keep in mind that alcohol is not part of the plan. What your husband will appreciate on the plan is that he can eat what he wants off the menu and not consider the prices. I don't think we really appreciate how freeing that is until you order that first DP meal!
Under Dining on this site you can see all of the restaurants in the 2007 program, look at the menus and decide if there are enough places you want to try, add up what you think you'd spend and decide if the plan is a the better deal. Keep in mind in 2007 your tax and tip are paid when you buy the plan, so everything is truly included.