We are close to signing a contract and taking our first
dvc trip. I was going to put 1 day aside to hop around and see all the properties so I can decide which one to buy next time.
1)Is this doable?
2)Does this make sense?
3) Would it be smart to do this with a car or not?
4) To make it fun for my older kids - are there suggestions to to do/see at each location to make it a nice day for them?
Thanks!
Despite what others say, I think it makes a lot of sense

We actually just did this yesterday, so to answer your questions:
1)Is this doable?
So they do a more formal "open house" that starts at Saratoga, and I think they have a few resorts you can see that way. Otherwise, you just have to go to the resorts that are selling to see the models (Animal Kingdom and Bay Lake Towers and the model at Boardwalk) and for the others not actively selling, you can just go to the front desk and ask if they have any open rooms you can view. Most cases, they will have some type of room, although maybe not the exact one you were looking for. The staff was super nice though when we asked about that. Beachclub even accomodated us at like 9:30 pm.
2)Does this make sense?
Yep, we actually changed our thinking about where we wanted to purchase.
3) Would it be smart to do this with a car or not?
Definitely use a car, it is way to hard to get from each resort without one.
4) To make it fun for my older kids - are there suggestions to to do/see at each location to make it a nice day for them?
At Boardwalk and Beach Club, your kids can walk around the boardwalk area and Beach Club has a great ice cream shop

. At AKV, the resort itself is really pretty, plus the kids can go to one of the animal viewing areas and see the wildlife. Wilderness has some cool stuff in the lobby. Not to much at BLT.
I hope that helps. Good luck and enjoy!