I think I would only add 2 boxes of Borax to start and see how much that moves the pH and then add more if needed. Also, I would only add a couple of lbs. of baking soda at a time. You don't want to risk clouding up the pool. The amount of CYA should be about right. You will probably want to bump your CH up to between 200-400.

Sounds like you have a good handle on things. Good to see you back on the forum this year!