New to the Boards.... UPDATED-NOW WITH PICTURES

[ASaterX5]

Hey everyone I'm new here, and I'm glad I found a place to have my X5 questions answered cause I'm not the most car savvy person. A few questions regarding the used X5 I just got...

First off, it's a 2003 X5 3.0i with 85k miles.

Now here are my issues...
1. At a stop it will shake from time to time I wish I could describe this better
2. Should I stick with getting my oil changed at BMW dealers?
3. What are some good products to increase my MPG's.
4. What should I do about some light scratches in the paint? Take it for a buffing or getting something and try it myself?

Thanks for any help!