see section 310.https://codes.iccsafe.org/public/document/IRC2015/chapter-3-building-planningFree codes:https://codes.iccsafe.org/index.html/

I was the lender they were the borrowers and when things went bad their tenants stopped paying they could would pay for a few months then quit and then I took the asset.. lost of drama lots of marital discord .. was not pretty.. but I am not predicting those times again I am hoping that was once in a life time.. but folks that had free and clear assets even if they sat vacant they did not lose them.. that's my point.. no most of my friends that made it owned business or were presidents of companies that went public and got monster stock payouts.. remember I am from the Bay AREA...

Except lease contract, statement or evidence of security deposit, move-in check-in list, what other documents should we get from the seller? 

Most of those types Pension Funds, Insurance Companies are investing with REIT's.The institutional money typically only invest with the whales for what they tend to perceive as ultimate security and low risk.I talk to REIT's all the time looking for off market properties for my clients.

X, Due to public records I have been made aware that your property in XYZ county and XYZ state is currently delinquent for non-payment of property taxes.

Will banks sell individual notes to the public?

I would also look at ways to stagger the lease maturities so they are not all turning over the same year.I would want to try and secure these tenants for 10-20 years if I am building a new facility for them.

My goal is to have every one feel secure in the partnership while also avoiding any unnecessary fees like legal, if possible.

(this is not very likely because of your lack of experience and high LTV) This lender would be in a 2nd lien position and not very secure if you fail. 

I should have funding secured for the area I'm looking at in the LA area.