There were no formal terms or expectations - it was just "here's the money, don't be dumb".

.+ Formalities can be taken care of very easily, they are using the online system called DocuSign and you can sign everything online.

There are two different issues at play - the titling and ownership of everything is more of a legal liability issue.It is possible to still have a tax partnership just with execution of a JV agreement, even if there is no formal LLC in place. 

We are planning on getting one more estimate not a formal one yet but a rough one from another trusted contractor.I put this information in a Google sheet and that is where I got the profit number. https://docs.google.com/spreadsheets/d/1HpdX8GG4tDZVtfVykfs6...

Keep conversation formal and in writing as much as you can.

Most lenders will do a hard credit pull before presenting a formalized term sheet, but that is after a property is under contract and your offer is accepted/you submit a full application and send in a credit authorization. 20% down with no STR experience is pretty normal on the market, but you will likely be using a haircut AirDNA projection instead of the full 100% to qualify you. 

You must send a formal notice informing the tenants that AB 1482 does not apply before sending out a rent increase notice.

I understand that there won't be any cashflow but the loan paydown and appreciation over time hopefully offsets not having cashflow.Legal and Financial Advice:Do you have any recommendations for legal or financial considerations we should take into account when formalizing this co-ownership agreement?

This can allow for favorable tax treatment and potential tax deductions related to the properties.Management and Decision-Making: Establishing an LLC can formalize the management and decision-making structure for the properties.

The only magic is that in 2004 the IRS formally made ownership of a membership interest in a Delaware Statutory Trust the same thing as owning the real estate itself.