You can make minor adjustments based on the type of appliances (dishwasher, clothes washer and dryer, air conditioning, etc.) and the size of the rental.

I had a tenant force me to pay for some dumb azz air quality test where she claimed my air was bad and making her sick. 

If they do it outside and do it recreationally and not in absurd quantities, it will air out in minutes. 

I have smelled it in the halls and in the other tenants air vents.

Where are you getting your Air BnB projected revenue?

Can you actually sell your Air BNB as a business?

I used the radiator key to let the air out and 10 mins later the radiator was hot.

That is something I would for sure have to look into as, according to your post, it seems like the timeline for mid-term rentals kind of lines up with the amount of time that we would be gone each year, which would work out well and probably require less of a hassle of trying to maintain the property after each stay for Air BnB.

Its my understanding that SF has pretty tight Air BNB restrictions like you have to register and can only rent them a certain number of days a year?

I can buy a 2-4 unit with 20% down vs conventional can only buy a 2-4 INVESTMENT property with 25% down 4. there are options where DSCR loans dont repot to personal credit, helps in not having to show a bunch of paperwork or not one person in a partnership has to carry the debt5. way less paperwork to close on this loan type vs a conventional loan. we care about the income of the property you're buying and it's ability to service the debt of the property whether we use long term rents income, lease income, or air dna/bnb income.6. easily buy in partnerships, add people to your operating agreement, its as easy as that so bring partners into a deal. helps with scaling and raising capital or getting partners involved7. gift funds allowed to close on these as well, and like I said earlier, there's only a 10day seasoning period of funds with some lenders so that means you can literally have a private money lender deposit money into your account 11 days before closing, and you can use those funds to close!