When you check in they do have a book that rates each site as to difficulty level for backing in. If you tell the Cast Member at check in your request for an easy site they will definitely try to accommodate you.
My family and I love the Fort and have gone several times. Most recently this last July.
As far as golf carts. There is parking at the front main bus depot (the outpost) and parking at the marina (the settlement). There is also golf cart parking in the back in front of Trails End...
When speaking to Guest Services at Disney about the email I sent; they said golf carts didn't count toward the fee. Even though I don't stay at the cabins I told them it was bad taste to charge to park a car when each cabin has its own dedicated parking spot.
There is some availability in April - I'm guessing they haven't pushed their calendar out like they should for reservations. As I spot checked through May, June and July and April was the first month that had any availability.
Yes, quite a few kids. There was a coloring table for kids. There was a mixture of short and tall tables. I think those with smaller children used the shorter tables but there were still no chairs. Some kids sat on the floor with their food. The room itself wasn't overly crowded, there was ample...
I found the viewing location pretty awesome. The desserts and food options are actually pretty good. I like the fact that they had non dessert options this last summer with cherry tomatoes and cheese (light saber). One with olives and a couple of other appetizer options.