Just use a rubber sanding block to prevent that, and also be careful around corners and eges on the body since paint is thinner there

 

they got this stuff at pep boys that fixes that I forgot the name sorry but I do remember reading the back , its a spray actually , so goo there and ask them

 

For light scratches, using really fine sandpaper and a buffer will work great. I use 2500 grit. A sanding sponge or foam block work great for under the paper. Wetsand the scratches. Mixing a small amount of soap in with the water will help the sandpaper slide easier, and leave a better finish. Come back with a very fine compound to take off the high spots left over from the wet sanding.
Personally, I'm against most of the scratch removal polishes. By me experiance in a detail shop, they mostly just temporarily hide the scratch.
You shouldnt need to have the car repainted. That seems like overkill. If you dont want to try the buffing yourself (which i recommend against, unless you've done it before, because of the chance of leaving swirl marks) I would leave it to the professionals. Most auto body shops around here will run about 300 for an entire outside scratch removal/buff, but if there are detail shops in your area, check with them. I usually charge about $100 for buffing/scratch removal of entire vehicle.

 

I bought a product that as of yet I haven't tried but it's supposed to do a great job at what you're trying to do.

Langka Corp.

The product I ordered might work for the major scratches and any stone chips you might have...

I'm waiting for the weather to clear before I do the paint repair but I'm betting it'll work.

Try www.langka.com

I'll try to get a website and post it..