Yes, all those things to do besides the beach.
The things along the boardwalk, as you saw, are not only the entertainment at the several stages and the retro amusement park at 15th just beside the boardwalk, but also the family surries to ride and monuments and small museums in historic cottages. There are the small play areas in the sand beside the boardwalk and the larger one at 2nd as well.
Depending on when you come you could have a festival...seems to be something every weekend in summer.
You can also enjoy the Beach Street entertainment on Atlantic from about 17th to 24th. Stilt walkers, auditioned approved musicians, jugglers, etc. We really like Hilby on the side street...about 21st or so.
There's fireworks too.
Check out the schedules for your time at beachstreetusa.com and visitvirginiabeach.com.
If you choose Sandbridge there are shopping areas and restaurants nearby as well.
You would need to drive to the boardwalk but it's not so far. Once there you can park and walk easily. Lots of benches. If you find yourself too tired to walk back, just hope on the Wave bus along Atlantic Ave.
If you prefer the boardwalk section, there are a few places with 2 or 3 bedrooms...you'd probably want the three bedrooms like at Boardwalk Villas. Or you might like the cute beach cottages with the old fashioned front porches wih a view of the boardwalk or ocean at Cutty Sark. Go to their site and click on cottages. You might be able to combine two upstairs/downstairs units. DO note their cancellation policy. Reasonable for the privately owned smaller places, similar to inns, and understandably less flexible than large hotels.
The picture on the front is one of the cottage porches.
Edited: 2:12 pm, March 06, 2013