“We decided he would not try a foreign language (consistent with all of his neuropsych testing). At the HS’s suggestion, we partially homeschooled him.”
I don’t think avoid foreign language is an option for OP’s son and those are the kinds of classes that could be challenging. You don’t need to take AP but probably two or three years would be needed for the more selective colleges. Again, homeschooling is good suggestion but not sure it’s an option for OP.