change one variable at a time treating this as a single property. 

You cannot treat your tenants like you do your children.Guests dropping some trash out the window and giving out the front door code honestly does not sound like an issue.

Treat them with respect and be professional.

Hope the market has been treating you all well.

Else the tendency to not care and not treat the arrangement with respect, may arise.  

The IRS has provided a safe harbor for certain structural modifications to a building that are not treated as a demolition and thus, not properly chargeable to the capital account with respect to the land on which the building is located.

Tenants can make your life a living hell - treat them with dignity and respect and it’ll pay 10-fold.

When a tenant complains about mold best to go and see it for yourself or your crews etc....treat the area and see what, if anything would be causing it. 

Again, this is a coming from the perspective of treating MTRs more like a STR rather than a LTR. 

However, as the owner you still need to spend more than 50% of personal services and more than 750 hours on the real estate business on your own.Alternatively, short-term rentals are generally treated as active business income and therefore are eligible to offset w-2 income.Navigating the Real Estate Professional Rules"When measuring material participation, a married taxpayer is required to count any hours performed by his or her spouse, even if the spouse does not own an interest in the business or if no joint return is filed.32 While this rule is advantageous because it makes it more likely the taxpayer materially participates in the real property trade or business, it is a trap for the unwary in the real estate professional context, as discussed below in Step 3.""