If you google "camp games" or "scavenger hunts" you'll find lots of great ideas you can gear to the kids. I'd skip the rock climbing thing - it can be expensive, not everyone loves it (unless you're positive about every guest), and it kind of defeats the purpose to being outdoors.
My kid loved treasure hunts - we used those plastic Easter eggs (but you can find them in party stores year round) and also used little baggies. We put little candies or other treats/prizes in them, and hid them around the yard. You can assign each kid a color (if you have too many kids, put a sticker on some of the eggs of the same color - so Kid A gets purple eggs, Kid B gets purple eggs with a sticker.). That way everyone kind of works together to help each other get their designated prizes. You can just hide them randomly, or you can write clues. We put them in potted plants, stuck inside shrubs, in the bottom of downspouts, perched on the hose reel, in the V of a tree branch, under the deck, etc. etc. Here's just one web site.
http://www.camping-field-guide.com/camping-treasure-hunt....
It's good outdoor fun and they run around. You can also do a scavenger hunt where they have to find items in nature. Here's one sample list but you can find many others on line http://www.lovetheoutdoors.com/camping/kids/scavengerhunt...
I love the idea of tents inside - no bugs! Give them flashlights and let them turn off the lights.
Hot dogs are fun, so are s'mores. You can use skewers but remember the kids don't have much experience and the metal ones get hot. You can find extra long wooden ones in most grill and picnic sections. A lot of times people soak the wood ahead of time so they don't catch fire. Be sure to supervise the marshmallow part - there's a dangerous challenge that's been going around for a few years where kids see how many marshmallows they can stuff into their mouths. They soften and form a big glob, and kids have suffocated/choked. So get on top of them from the get go!
Another movie that people don't always think of but which stars a young girl is "Fly Away Home" with Jeff Daniels as a divorced father whose daughter come to live with him. (I think her mother might have died but that's really soft-pedaled.) They wind up raising some Canada geese that have to fly south for the winter, but there's no adult goose to lead, plus there's one that's injured. So they wind up flying those small craft that are kind of like hang-gliders with engines (Sorry, I'm blanking on the name). It's a moving about bonding daughter/dad, about conquering fears, about doing the right thing with nature.There's a subplot at the end about some big company doing damage to the environment where the geese have to get to in order to meet up with the rest of the flock. I haven't seen it in a long time but our kids loved it. You might want to check it out ahead of time. It's often available on demand or through the library DVD rental (free!).
You can just serve popcorn at night, and if you feel you really need to give out goody bag stuff, consider a canteen or some binoculars or other nature items.