Im worried about younger less reliable tenants. 

I think the bottom line is there is a lot more commitment that goes into property management than most people think, but if you have the time and energy to commit, go for it.

Could you suggest some reliable websites to keep an eye on current interest rate trends and forecasts?

Or if there are any reliable "coaches" I can consult with on the matter. 

Maybe become an agent and help them find deals or maybe they need a reliable PM , etc.

I always feel like one needs to have more than 1 or 2 reliable lenders.

Even flipping or wholesaling will still take some significant systemizing and scaling to reliably do $200K/monthPeople can "tell you" all they want, and anyone can sit here and speculate what is and isn't the best way to get rich or wealthy. 

On the flip side, my “brother,” and business partner, Rob, is the “Daredevil” This means he thrive in high-energy environments, embrace risks, and is relentlessly driven to achieve bold goals.

High energy in your post, but tread carefully.

Navigating appliance issues in a rental can be tricky, especially with a long-term, reliable tenant like yours.