Pretty much any regular bank / lender is going to require themselves to be in first position on all the properties... so I don't think a HELOC type solution is going to work across multiple properties with multiple lenders.  

In other words, I already have a checking and savings with BoA, but I would create a 2nd savings account (within my regular account) and put all the rental properties last months and security into that account (combined).Is this the correct way to prevent co-mingling of funds, or what would you recommend?

They were recommended to me by a local lender that I work with regularly.

I have people coming and going on a regular basis.

Keep in mind that tenant screening, regular property maintenance, and understanding the inspection requirements for Section 8 are crucial for success.

With 100 properties owned, with a regular property management you're still looking at at least 5 hours a week to manage them if you have good systems in place. 

We would regularly get emails with requests from new Kiavi staff or partners we had not previously been introduced to.

Regular and transparent chitchats are the way to go.

We regularly have people apply with fake SSNs.  

I love audio books and listen to them regularly when doing mindless work tasks or on walks.