First of all, DO NOT pay on that collection until you ask and get okay in writing for removal for payment. Medical collections will not short pay but still get that okay to remove in writing. I really wish I knew about them before I paid mine off, they are killing me.
Second, the late pays are not hurting you as much since they are more than 2 years old but, Good Will letter them. Since it is closed I would good will them and ask them to remove from credit report.
Leave Cap one open, you do not want to close an account even if it is 0 dollar. It goes towards your average credit life. Good will letter them asking them to remove lates. These good will letters are on this website. If you can still use charge 10.00 bucks on it if you have to. Although CL N/A might mean you cannot use it.
Collections that are paid I would good will letter them until they remove them. 1 a month I think is the plan everyone uses.
Good luck.