Your hull is gelcoat.
For surface scratches a rotary buffer and some rubbing compound should do the trick.
I use Buff Magic and it works well on minor scratches. You may need something more aggressive if the scratches are larger. This should also work for your decal marks.
Like I stated above, I use buff magic and finish with Pro Polish one time a year with great results.
If you choose a different product(s), make sure they are for boats only. Do not use car wax or polish.
Gel coat is tough to match color wise, so I've always paid to have it done right.
I don't have bottom paint, but I am sure someone will respond with a good product for you to use.
Good luck.
PS. Here is a video link for a review of buff magic and pro polish. It will give you an idea of the result you can expect.
http://www.boattest.com/products/Product-test.aspx?id=25