I am looking to partner with a close friend of mine (we've worked together many times before with both of us in various roles) to primarily do rehabs for LTR and/or resale.

Am I better off just waiting until the refinance is complete?

Still no estimate for completion yet.

If I purchase in California, I would most likely do a House Hack as my primarily.

Primarily desert washes, but also near a creek....So I would go knock on doors and ask neighbors when it has flooded and what they think about the area......maybe call the County water board and ask then what has happened there in the past.

If it's a good asset(meaning primarily good location), you eat the 5.3% cap no problem you own the physical asset.

Proximity to mass transit (mentioned by another poster re following them), proximity to downtown (maybe not so much now with work-from-home being a thing), proximity to airports, highways, pollution-belching industrial plants, hospitals, universities, the lake, etc., all help to define which South side neighborhoods have what it takes to overcome market inefficiencies and become "up and coming."

One place that will soon become a rental market heaven is an area around Johnstown/ New Albany where a huge Intel plant is under construction with plans for thousands of employees, not to mention the contractors there now. 

This primarily.

I primarily work as a part-time CFO for new (and "old") real estate developers and investors, primarily helping them financial analyze their deals and finding them the best rates and terms for financing.