I agree with the other posters. Request 25k through Amazon like every fricking week! My girl friend started out with a $2600 limit a little over 5 months ago and is now at $7000! She is only 18 and has a bunch of credit due to my guidance 
But back to your question...I would try to combine those Cap1 Accounts into one card so that you have one big limit. This will look good to other creditors if you handle it responsibly as it shows them you can handle higher limits. Also don't accept any CLI's from Cap1 unless it's like twice your limit or a few grand. If you turn it down they will just adjust their offer a gain in a week or so and most times its higher than the original offer. Believe me when I tell you this..I've accepted a $150 CLI before when I was new to the credit game :/
I would also cool off on the store cards. It looks like you have a bunch that you probably rarely use and just applied to them to gain some credit. I can tell you first hand that this isn't so great because it's taking away possible CLI's or higher starting limits on cards you really want to use!
Also like other posters have said before, cool it off on the inquries. They will affect your CS for 1 year after the date is was added and completely fall off after two years.
I'm also not that much older than you though so I can offer a lot of advice so just hit me up anytime you have a question!