... I could pay off $1k and get the balance under 40% (but CC util was my first positive on myFICO).
Finally, I could probably get on one cc as an AU, but I am not sure this will increase my AAoA by very much (since I have so many -- 19 revolving).
Adding an a card as an AU might help, but that will depend on your details and the details of the card to be added (age, utilization, credit limit). What is your current AAoA in months (keep in mind that FICO rounds down to the nearest year). You are at 18% overall utilization (if I remember correctly). If you can get that number below 9% you would see a jump. This could be done by getting CLI on any of your cards, paying off the balance, or by adding additional cards (AU only--no apping right before mortgage).