It looks like they tend to last longer and cost less to maintain.

Properly built and maintained log cabins can stand for hundreds of years.

The verbal agreement they had was the manager gets free rent for managing/maintaining the property including repairs, etc.

I do not charge extra pet rent or non-refundable fees as I want them to have the incentive to receive the entire deposit back if they maintain the property.      

I absolutely respect the fact that your tenant wants to maintain the quality of your home :) I do however think that these items are resolved at move out. 

get the other side rented out properly, with proper contracts, then also properly maintain seperate accounts for the rental income and expenses and bookkeep properly. stay firm but friendly as a landlord

The idea behind it, is that if the community is not structured correctly, these are all things that lead to the property not being maintained correctly, or the hoa owes some people money and that leads to assessments, which leads to you not being able to afford to pay your mortgage. 

A question that may have been come up many times before but I will ask it anyway, what’s the best strategy to be considered as RE professional for tax purposes while maintaining a full time W2 income.

use capital from banks at 5%.Stage 3) maintain 100+ properties and replace some of the SFR with   multi-unit apartments using all debt.  

Do you charge for monitoring and maintaining vacant units?