OK. Wow. Great trip.
My family went in the summer of 2010 on a very similar trip. My oldest was nursing an ankle injury so we were very limited on where we could go. We still had a blast. Also, don't bemoan being a tourist. These are great places to be a tourist. And, after all, we are all tourists, just different kinds. I'll browse through my pics and suggest a few things:
1) Old Faithful - Do it early. It is neat but definately not the best experience in the park. On the plus side it is, well, faithful so if your 6 yr old is impatient, the eruption window is fairly well defined.
2) Funnest geyser - Castle Geyser - A little away from the biggest crowds. The eruptions window can be a couple of hours so you have to be prepared. First, just plan to be in the area--the eruption lasts about an hour so you don't have to be there before it starts, just close enough to check in at a distance for awhile. You get a lengthy water eruption followed by a lengthy steam eruptions. We took a deck of cards, sat in the morning shade and chilled. The eruption crescendos slowly with several bursts until it really gets going. I liked it because it just kept getting better and better.
3) Chuckwagon Dinner in Paradise Valley near Roosevelt - You can travel by horseback, chuckwagon or stagecoach into paradise valley for a stake dinner and a cowboy sing-a-long. My kids loved it. If you go, sit up front. They invite a couple of kids ride up front with the driver. They made friends, pet the horses and ran around having a grad time.
4) Yellow Bus Tours - OK. Don't throw me out of the forum. We did the wildlife viewing tour and it was good. You're much more likely to see a grizzley or wolf if you have someone who knows where to look. The yellowbuses are neat as well. They were specially designed to tromp around Yellowstone and Glacier.
5) Young scientist/junior ranger programs - my daughter did the young scientist program. We got a backpack with some cool equipment (like an infrared thermometer) and she completed some objective in the upper and lower geyser basins.
6)Drive Old Gardiner Road from Mammoth to Gardiner - This is an old wagon road. It may say something about 4wd but we did it in a Honda Odessy so any vehicle will probably work. We saw lots of wildlife and good views.
7) Look for moose in Moose - Stop in the visitor center and ask where to look. We had no trouble finding them.
8) See Menor's Ferry and General Store - We were too early to see the ferry in the water but it looked awesome. The store was fun. It is stocked with period items for sale. Buy locally bottled root beer and sasparilla and drink them sitting on the front porch. There was almost no one here. My youngest daughter (who has the personality of a little boy) loved the place.
9) Enjoy the views -
I have several pictures here:
http://thornsberry.smugmug.com/Travel/Wyoming/Yellowstone-2011/19976343_KM88MR
and here
http://thornsberry.smugmug.com/Travel/Wyoming/Grand-Teton-National-Park-2011/19977098_WDFsWX