Since this house is one I Airbnb part-time and live in part-time it's more painful because I have to experience and see all the issues myself!

Some of it is just a royal pain in the ***.

I made enough mistakes to cause enough pain so that I crawled into a corner and curled up in the fetal position for 30 years.

I lived in Los Angeles, so I get your pain.

I paid PMI which feels painful but if you keep your eye on the long term prize it's worth it. 

Will it be a painful experience?

Now granted this is rare to the extreme but if your the one losing out its painful.

There should be other options, however with an LLC and fourplex - yes, DSCR is by far most likely to be your best option unless you do the heavy lifting with local banks and credit unions (and these are increasingly not great options for this type of stuff as they move painfully slow and are under lots of regulations and restrictions)2) I haven't yet reached out local banks, but seeing the quotes from brokers makes me wondering if Banks may be better? 

@Loan NguyenAs someone who grew up in the Bay Area (just north of San Francisco), I feel your pain. 

I feel your pain.