According to those sources, it is not a southern CA specific issue.  

Does this mean they're technically violating lending rules/regulations by not informing the lender that the property will be sourced as a rent-by-the-room asset? 

-sourced income.

I would be leery investing in a cash negative property with the only profit source being appreciation.Good luck

I’ve sourced a few off market properties that are closer to $400-$500.

You need options coming into the net from a few different sources.2) You need a panel of analysts. 

I never cared what they are making as the assignment fee, as long as I knew the numbers worked on my end.As for a purchase & rehab lender that will finance up to 100% of the wholesaler's assignment fee - I can introduce you to one that finances that and also 100% of the purchase & rehab up to 65-75% of the ARV.As a lender I sometimes receive off-market properties from wholesalers and other sources and share them to our borrowers if they fit what they are seeking.

I think whenever you are getting advice from someone it's important to always consider the source to identify the incentives that person has to give a certain answer and how it colors their thoughts.

Can someone recommend any advice on anything (setting up partnership structure, accounting/ setting up a bank account , lending with foreign investors, sourcing deals etc…).

While the IRS does not mandate a physical site visit, the IRS cost segregation audit technique guide (ATG) does suggest conducting “field inspections.”It’s important to note that the ATG is not an official IRS document.It serves as a guide and cannot be used, cited, or relied upon as an authoritative source.However, the recommendations in the ATG are worth considering.According to the guide: “A field inspection is recommended to document the physical details of the building, type of construction, materials used for construction, the assets contained in the building, the size and types of building systems, and any land improvements that were included in the purchase of the property and the condition of that property at the time of purchase.”So while the IRS does not require a site visit for cost segregation studies, following the guidance from the cost segregation audit technique guide can be beneficial.There's this thing called Hierarchy of Tax Authority that CPAs and Tax Attorney's reference.Let's not get too carried away with comments like, It serves as a guide and cannot be used, cited, or relied upon as an authoritative source....