How would I know the sewer or foundation isn’t rotting out below the building, or that there’s going to be a huge assessment to replace siding in the next few years?  

You don't want to use a comp that had foundation problems only disclosed in the Private Remarks.

Seller financing hasn't worked, but seller came off price to $100k (was $125k). 930 sq ft 2br 1ba raised foundation on 1/2 acre - lake Livingston on one end of the street and Trinity River on the other end of the street.How do we move forward to cover $100k mortgage? 

I am unsure as to the foundation of the cottage, but the modular portion appears to have been a poured slab (approx. 5" deep) with concrete block skirting. 

I think there are things you can learn to build a great foundation for managing your own units.

I learned as much as I could online in order to get a small foundation of knowledge, then I found a mentor who was already successful and learned from them.

Mathematics is the language of the physical universe, and is the foundation upon which all of science, engineering, and architecture stands upon, as well as everything else.

We also can't have renters dealing with the humidifiers as it is a mold problem/foundation issue if it isn't taken care of.We are taking pictures and videos of everything, we have multiple professionals that have documented everything (and told us to lawyer up) and have neighbors that we have already had agree to discuss their drainage problems when we get a lawyer.  

Find out more Sep 9-10 when the non-profit US Hemp Building Foundation hosts HempBuild 2021, an online conference with dozens of speakers to educate and inform on this exciting new green-building industry. 

It's great to see that you have a solid foundation and strong relationships, which certainly make a difference.