You are look way below the Middlesex County limits.I totally understand not wanting roommates, however, the ability to supplement even a condo with roommates can be phenomenal and an easy way to get started in RE investing.You final question has a few concepts packed together:1. -$100 a month does give you some tax losses plus the depreciation.

What questions should I be asking and what does proper due diligence look like for international investments like this? 

This gives you the ability to learn and have a mentor at the same time and a 5-10 door is just as hard/easy as any other loan to get.

It’s easy to get analysis paralysis though.

We have to physically go into a bank for the deposit since it's easy to blow past the number of check limits and/or the dollar amount limits.In our case, we're doing commercial real estate so the check values are high per month.I would love to ask our customers to do ACH / direct deposit, but they're not always amenable to that. 

I'm unable to remember who created it, so can't give the proper credit, but here's the link.

Btw, the example I gave up there with 50k profit was just for easy numbers, that's not a norm.

I will need to get the exact numbers from the lender tomorrow on what the new payment will be on the initial two properties and the new one to do the math....Easy enough to calculate based on the numbers you gave - Principal balance of $214k, 25-year am at 4.9% is a P&I payment of $1,238.59. 

Many go into real estate investing without doing the proper due-diligence, but you are quite the opposite.

While listening to podcast #283 (which you should listen to in case you haven't), Paul mentions that when he wants to buy a house, he sends the homeowner a three-option letter of intent with the following options: Cash offer (percent of what property is worth minus repairs, typically 50% of after repair value, this is the lowest value offer of the three that are given)Owner financing (interest only, this is a higher offer)Owner financing (principal only, no interest, this is the highest offer)Option 1 is easy to understand, the ones I don't know how to apply are 2 and 3.