A $25 increase is a bit more than nuisance but as long as it's in line with the market, you should get them to accept.

The ducts/vents of the house were cleaned not to long ago and the tenant wont let the PM have more testing done or mitigation. 

Could do this all day long. 

Personally, I'd recommend multiple properties, but that all depends on your long term goals.

The current long drawn out detailed and tedious process causes tenants to delay until the point of no return.

I invested in a syndication in April of 2022 that was projected to give me an 18 percent return for 4 years after which I would be refinanced out on a waterfall and left with 5 percent of the deal post the waterfall as long as the deal is owned by the GP.

For a long-term hold that isn't a big deal.  

If you're confident in the Bay Area's market and foresee returning, renting might offer long-term benefits.

I am also on the fence considering that NPR is not that desirable a community. 100K purchase price with a $900 odd rent amount would go a long way in better, more stable cities.

Really your question would be, what are all the possible closing costs and there is a long list there, I suggest getting to know a local closing company to help you and they should have some info on a website.