If your first priority is to have rooms that are close together, contact DVC Member Services and have them put a "traveling with" designation on the reservations. The resort should prioritize assigning rooms that are close by one another. If you do this, I would suggest foregoing all other requests. Hotels aren't like cruise ships where everyone arrives and departs at the same time. They have to do the best to accommodate you based upon rooms which are being vacated on your arrival day.
We have traveled with friends and been assigned to rooms right next to each other. Another time we were one floor away.
Generally speaking, all of the Standard View rooms at Riviera overlook the parking lot and face toward the rear of Epcot. Preferred views face toward the pool / lake and Caribbean Beach resort. There really aren't many "bad" views, if any. The biggest complaint I hear is people who have preferred view and are disappointed that they are looking at the lake rather than 20 minutes of fireworks.
For dining reservations, your best move is probably to make 2-3 separate reservations and ask to be seated close. Stick to less traveled locations and you'll have greater success. Sebastian's Bistro at Caribbean Beach is a 5 minute walk from Riviera and I keep hearing good things about it. The dining board can probably offer more advice on this topic.