I don’t see one period of being a TA as an issue but:
–Have you taken a foreign language through level 4? If not you should continue foreign language.
–Have you taken biology, chemistry and physics already? If not you should finish this sequence before taking APES.
–Have you taken calculus already? If not you should consider taking calculus rather than AP Stat.
If you are aiming for elite colleges it is worth the time to talk to your guidance counselor and be sure you will be taking the most rigorous schedule available at your HS (which is not necessarily taking the most APs possible). For example, AP Stat is typically not considered as rigorous as calculus and APES is generally not considered as important as having at least HS level bio, chem and physics and is not considered as rigorous as AP Bio, Chem or Physics.
And FWIW college admission officers don’t typically care about self-study APs. They are interested in seeing how well a student does in a class, not how well one can cram for an exam.