We've been going to HHI for almost 20 years, and just bought a villa there. So I guess I can give you some ideas about places to eat! However, we've always gone to Sea Pines, and the beach varies a great deal between locations. Haven't been to the beach up your direction. I know that the DVC is not on the beach...you either walk a path which goes under the main highway or I think they have transport. HHI is known for wide, sandy beaches. Sand is softer than the Outer Banks, and the overall look of everywhere is much more pleasing. Amount of waves, and the distance you can go out from shore varies greatly from one part of the island to the other.
For food, there's the Crazy Crab (two locations--one in Harbor Town and the other on the northern end of the island). Pretty good for families, heavy on seafood though. I prefer the Harbor Town location for dinner because I love their hush puppies. Kurama is a great Japanese steak house. Sticky Fingers just opened, and is great for ribs. Other rib location is Tony Roma which is also good. Be sure to go to the Salty Dog Cafe in South Beach in Sea Pines. During the day it's mostly outdoor service--a bar kiosk on the decking around the South Beach Marina. In the evening there is outdoor service offering a "cookout" type menu and also indoor service with a nice menu. If you're there during any "high season" they have outdoor entertainment in the evening. Cafe at Wexford is great for lunch, and Tapas is wonderful for dinner for adults and older or more adventursome kids. My kids are older, and have always been fairly adventuresome eaters so we really haven't done much with pizza or stuff. Oh, Hilton Head diner is also a pretty sure bet.
For entertainment there are several mini golf courses--not the putt putt variety, much nicer. Bike trails galore. South Beach is home to Captain Zodiak, which offers dolphin watching via motorized rubber rafts. Much nicer and more personal than the larger dolphin watching cruises. There's parasailing and water craft rental available at South Beach also as well as fishing charters. Be sure to go to Harbor Town to see Greg Russell if he's performing while you're there. Even though they're 17 and 20, my kids still get a kick out of seeing him. Shannon Tanner (?) is at Shelter Cove and I've heard good things about that performance also, but have never gotten there.
Outlet shopping is just off the island--2 malls worth. Character Connection in one of them. Often decent bargains. The two on the island have declined dramatically in the last couple of years.
Obviously we really like the island, or we wouldn't have bitten the bullet and bought a place. With the snow over the last little while I'm really sorry that it came with winter renters in place or I'd have bailed and gone down! Hope this helps, and let me know if I can be of help.