Since there aren't any major banks that enforce dual signatures on accounts, an idea I had was to use a licensed and bonded 3rd party custodian account which requires dual signatures before disbursement.

I belong to a few forums (expats in Italy - etc.) as well as hold dual-citizenship. 

The simplest way to view debt is through the dual lens of risk and opportunity.

I never allow dual agency.

Why have the dual distraction? 

Assuming you are a real estate agent you need to have them sign the disclosed dual agent form.  

Like @Eric James said, if something is in decent shape, don’t waste money upgrading.If you have single pane windows, upgrading to dual pane vinyl frame is a worthy upgrade.

Now if you have two houses, you can theory pay off one house from equity of other house.ARM when combined with multiple house in acceleration city is like dual turbo charge engine for money printing system LOL

I will try to make sure to have decent tenant screening as well as have dual diligence on contractors 

my wife and i are 42 years old, dual income, no kids (working on that)... we bring home 15k/month after taxes. we save at least 2k a month. our mortgage is $3700/month, locked in at 2.875%. we don't want to/care about paying it off as any other income (stocks, etc.) will easily beat this rate over time.we have about 200k in investments, 20k in liquid cash (spent 150k or so in the last year for health, fertility, and home renovations), my 401k has 775k, wife's has much less due to health issues...we want to either buy rentals (i see this is a rocky risk) or small businesses (Codie Sanchez just opened my eyes to this). other options that sound feasible?