My understanding is this way (may not be right):

1) 5 cards is not too much. No need to close any of them only because of it.

2) call the 200 and 1500 cards, let them get your limit higher. Higher limit will help your scrore. Very high limit (in your case, 10K or more) may not help, but may not do bad as well.

3) when using a card, never use more than then 1/3 of its limit.

4) try NOT to close your first cards. It will help you. Just leave it there.

That's it!