Ten (or a hundred) years from now, the balance would still be $900K.In order to eventually pay of the balance, the interest has to be paid plus an amount to reduce the balance with every payment.

The "issue" I'm having as of late is that I've automated a decent amount of the work processes here, which leaves me with a lot, and I mean a lot, of spare time on a weekly basis.

--Take out the HELOC on the rental and my stockpiled cash and pay off the mortgage on my main home in full and call it a day until the crash comes along when I will have likely saved up more money and have equity in my home, but of an unknown amount.

Data offered (there will be differences in the amount of data available on a given property)4.

Will be well over a million even though the principal amount is less than a million.

You should check how long Bayonne didn't do a re-evaluation for that matter and be prepared (depending on your neighborhood) to have doubled amount of taxes. 

Good Afternoon Investors, Is there a rule of thumb you follow for targeting the amount of cash left in a BRRRR deal post-refinance?

If both units are occupied with month to month leases, am I obligated to keep the current tenants or can I give them "X" amount of days to vacate the property upon closing or the like?

I think you should examine your projected rent amount very closely.

If that hole has been there any length of time its very likely you've had significant amounts of water inside, given Houston's weather.