It's too bad you arn't happy.
I think i can help on a few
1. If you get like a thump as you stop/ as the weight settles to the rear it usually the propeller shaft/driveshaft that needs to be lubricated.
Link
3. Sounds like you have an open rear differential. Better tires than stock help, but a limited slip is the best bet.
5. I have the same problem. I think its the air thats still in my brake lines. No one else bleeds them well, so i'll do it myself eventually.