First, for UCAS you only need one piece of writing - your Personal Statement, which is sent to the (up to) 5 unis you will be applying to, so don’t worry too much about that with regards to having too much writing for UCAS to make EA deadlines.
Just wondering why you are applying for history of art at Oxford, and just history at Durham? It will be difficult for you to write a personal statement that is convincing for both history and history of art. Did you not like the history course at Oxford? But tbh, history of art would be an easier admit as you will have AP art history, whereas with history you would be fighting an uphill battle vs UK applicants with an A-level in history.
Are you planning on retaking AP world history for a 5? Have you taken APUSH? WHat other APs have you taken/are you taking?
How set are you on the UK? If you want other UK unis that are maybe easier admits whilst still a bit similar to Oxford, Durham, and St. A, maybe have a look at Lancaster, Loughborough (pronounced luff-bruh), Exeter, Bath, and maybe Kent. Nottingham, Newcastle, and Surrey could be worth a look as well.
Definitely keep Williams if you like art history.
It seems to me that you want rural/small town? If this is the case take off George Washington (doesn’t even have a proper campus), St. Johns (as long as you mean university and not college), Syracuse, City college (SUNY New Paltz and Geneseo seem like fine safeties), and the American University of Paris (not familar with it but guessing by the name).
Bentley and Babson are business focused so agree with taking them off.
Madison is massive; not what you want.
What really helped me with cutting my list down is separating each school into reach, match, and safety and then focusing on cutting each group to a certain number which makes a huge list seem less daunting and easier to tackle. 3 safeties should be more than ample, unless you are shooting for merit scholarships in which case more will be needed. However many reaches and matches will be up to you.
Have you thought about what character of LAC you want? Large Greek life vs minimal, a very ‘intellectual/bookish’ atmosphere by work hard play hard. Again, rural/small town vs urban. The culture of the school will be very important for LACs.
Good luck!!
PS, I’m English so if you have any questions about UK unis or living in the UK, I may be able to help.