Oklahoma may require you to file a state tax return regardless of your income level.

Furthermore, going direct to seller requires patience and people skills.

I've used the Avail leases before and a lot of those pages are dedicated to required CA disclosures like the lead paint acknowledgement.

- Am I able to do a mortgage assumption from personal to the LLC to avoid the balance being called and effectively keep the interest rate?

Lowest down payment requirements, typically only need to occupy for 6 months, can take cash out like any other property and effectively "BRRR" minus the rehab. 

The bank says your “insurance company” needs to pay off the $450k mortgage balance, where’s that money coming from?

We own over 600 apartment units in Cleveland Heights, Lakewood, and Mentor OH, of which quite a few require rehab to bring to market rent.We struggle to find enough contractors for this work.I know that this is a common problem, but if anyone has any recommendations for contractors in that area, that would be awesome!

That's not possible...If you signed a contract for $100k, that's the price 'until and unless' there are changes requested by you OR required by circumstances (in-wall wiring is frayed. headers are undersized, etc)Second - Please don't breakdown the materials and buy them yourself.

I'm new to the BRRRR method, what are the requirements needed by a hard money lenders to fund a project.

The fed is going to keep a tight position as long as they can...until stuff breaks so they can vacuum up the massive amount of excess stimulus and decrease the size of their balance sheet.