Of course you can use polish! It won`t fix the chips, but you can probably get many of the scratches out or minimized. You may want to use a clay bar on it first to get the ground in debris, but once it`s ready use a good carnauba wax to shine it up. I use Meguiar`s paste wax.
I've also had good luck with Meguiars products, specifically Ultimate Polish and Ultimate Compound. If you don't feel the scratch, it more than likely can be removed. If you feel the scratch with your fingertip, you will not be able to remove it.
If you want even longer protection from the elements, use a paint sealant. With Rejex or Collinite 845, I typically get at least 6 months protection.
For more info about taking care of your car paint, visit the autogeek website.
Yeah the polish will only work on the parts where there is paint and clear coat left. You'll have to use a dual action machine to really get scratch's out. Doing it by hand can only really do so much fyi. After you are done polishing it's best to use sealant cuz that will lock in the polished job then wax on top of that as mentioned above earlier.