I would start the eviction process and it will either scare them into paying up quickly or you will at least get them out sooner by starting now instead of delaying it further.

Minimal upkeep, industrial strength supplies at cheap prices.

Those are generally limited to things such as violations of habitability, military duty, landlord harassment.Under CA laws, landlords are required to minimize losses if a tenant prematurely vacates a rental.

Capital expenditures are minimal with the the recent reno and a property manager told me they'd be easy to rent and may be able to slightly increase them by a few bucks every month. 

Minimal appreciation in Bakersfield compared to elsewhere.Try looking at Tehachapi area if you are near Bakersfield.

Hi, i m new here, any advice on what Minimal cash on cash return for rentals should look for? 

@Jeff Williams, I think the impact will be minimal and you likely won't get your money back (in terms of appreciation) by converting to HVAC.Who owns and maintains the window A/Cs?

The advantage of buying cash is not having to go through or to the bank twice to get financing - first on purchase, second on refi which they may or may not want delay/seasoning time.

They look at BCAD which can be rather delayed. 

The red tape was minimal, and if you find a contractor that specializes in ADU's the numbers may make sense.