They offer invaluable insights into neighborhoods, regulations, tenant demographics, and market conditions—information you can't get from books or podcasts.The good news is that working with an investment team typically comes at no extra cost.

I can not name any reasons which are worth the extra effort of investing there compared to sticking to a specific USA market.

Helps with your debt to income, better opportunities at cash flow, and typically requires less down to purchase.In regards to challenges, I usually build in an extra 10-15% to deal with things that I can't see behind the walls, including dry rot, electrical or plumbing issues, etc.

It tends to hide marks better.Walls: Neutral tones like SW Repose Gray, Behr Swiss Coffee, or Moore Classic Gray are renter-friendly and modern.Trim and Doors: Use a crisp white like SW Extra White or Moore Chantilly Lace.Accent Walls: For a touch of style, consider an accent wall in soft blue-gray. 

You'll likely pull a few hundred extra dollars and will will get shorter leases that could work better for your traveling.

I'd hate for a temporary dip in the quality of the tenant pool to be giving my landlord "spidey sense" false alarms on account of taking an extra month or two to fill a unit.

From what I can tell, the extra equity on the house could be utilized to provide better ROI.  

-A water heater issue resulted in repeated mismanagement—confusing unit assignments—leading to extra costs to fix the same issue 3 times and on each occasion "more fixes" needed to the water heaters that I plumber said was needed.

First, estimate what the renovation would cost, how long it would take, and how much extra you could potentially sell the property for once it’s fixed up.

Rigorous screening.