One of the requests was that I get an official invoice for any outstanding balance for each property.

A HELOC can work for this, but keep in mind it has a variable rate, so it isn't the best product for keeping a balance long term. 

These relationships, if cultivated properly, will allow your borrowing to outpace your balance sheet.

I am a Realtor and have a seller that has an assumable loan, but that still leaves $300K between the balance and the sales price.

In a simplistic metaphor, the FED needs to balance out the health of the economy with inflation.

@John Kunick, Thank you for sharing the article The Pros and Cons of Rent Control for Landlords and Tenants and your balanced perspective on rent control.

It is figuring out what your capital needs are and what your short and long-term goals are, then matching your debt strategy to balance those goals and capital needs.

However as a wholesaler, there are those of us who take pride in providing a well balanced deal where all parties involved are happy.

It doesn't really make sense to have two of these loans open with balances, because that just dilutes your cashflow. 

When you tell these people that it often takes more than a decade before the investing makes things like that possible, they go looking elsewhere for advice, until they find someone who's willing to sell them what they want to hear.Building relationships, improving your lifestyle, relieving chronic anxiety, creating strong friendships, building bonds with family, work-life balance, delayed gratification, risk-reward management, lifelong financial freedom, all the really good things about REI are often suffocated under the overwhelming need to GENERATE INCOME TO QUIT MY HATEFUL JOB.What's the best thing about investing for me?