I can't say I agree with much of this. Where are you looking to try to find off site deals? We use VRBO and have never, in at least 10-15 different stays, paid a parking or resort fee. The only fee we ever pay is a cleaning fee, which is usually around $75-$100. For our upcoming trip, we're very lucky to be able to stay for 17 nights. I'd have to go find my rental agreement, but I'm paying something like $1175...all in. Includes taxes, cleaning fee, etc... That's for a 3 bedroom, 2.5 bath house. Not going to find anything like that at a value resort on property.
I certainly do agree with having a car and not relying on shuttles. If you don't bring your own car, rental cars are super cheap in Orlando due to the competition.
If you're from Atlanta, like I am, then you realize what real traffic is. The "traffic" around WDW is not bad at all, even in the middle of rush hour. We've never had it take us 30 minutes to go a few miles. Sure, some of the roads are heavily congested, but they don't take THAT long to get through.