Here is what I would submit:- Get Educated:  There are endless resources available to aspiring real estate investors today. 

I think you need to develop a pricing model and stick to it, and then always be widening your network of sellers. 

As an aspiring agent and investor, should I expect more lessons like this to occur via trial and error?

This is across various manufacturers and models.

Consider asking them to share in the re-modeling for maybe a reduction in the rent.

Sounds like a complicated business model where each business/property is dependent on the other.

Seems the takout/delivery model would be more viable moving forward, and would save a ton of resources with no retail, high visibility location, much smaller footprint, delivery personnel instead of wait staff, no dishes to clean, etc. 

I'm convinced MetLife uses this as their business model. 

I will look into the licensing and if needed revisit my business model.

If they have been good otherwise, use my model.  ;-)