That's quite a list of issues. Did you check Kelly BlueBook on the price/value? http://www.kbb.com
The body rust scares me more than the mechanicals would, but that's because I don't know diddly about doing body work.
Now for my answers on the numbered questions.
1. Could be u-joints. Only way to get a good idea is crawl under it and play with the drive shaft.
2. Already commented.
3. This could be a lot of things. Have to know what gears are in the differential. Either check the tag on it or call the dealer with the VIN. My brother has an 04/2500 Hemi and it has plenty of pep.
4. The thud could again be the u-joints. Just remember to check all of them.
5. You didn't say if this is 4x4, but if it is you could have a half-shaft gone or going. If 2wd it could be a bearing or control arm bushings or just about anything in the front end.
6. Bondo means fixed damage. Body work again. I plead the fifth.
Bottom line is if you are good with your hands and have the place to do the work just about anything is fixable. Question is how much you want to fix vs drive it.