One of the applicants is a Section 8 applicant in the state of California.(1) I want to be conscious when screening tenants, I am wondering should I have them all apply at once and play $40 for application fee, knowing that only 1 tenant would be able to stay?

Some areas have expensive water and sewer tap fees and others are cheaper.

We discussed selling or doing a 1031, but the commission would be about $50k, and we don't want to lose that now. 

With high fees and the grip Airbnb has around your neck my goal for 2024 is to get it down below 25%.

Picking up the phone and discussing with them is best when you have a specific property to discuss, otherwise their website has good general information. 

Then I file a landlord complaint for possession. 9/10 they pay late, but they pay the rent along with the late fee by the middle/end of the month and then the cycle continues.

I'd have to double the security deposit, raise the rent by 20%, and double the cleaning fee to even make it worth considering-- which I would if people were willing to pay but the market doesn't support those prices.

That was way more than my REIA fees.

I really do not want to sell the Condo because I do have a 3.5% Interest rate w/ a positive cash flow of about $450/month, even after the $330 HOA fees. 

Heck- this legislative session, the state just passed a law stating that no city can pass any laws regarding rent controls or limiting the fees that a landlord can charge.