You should ALWAYS assess late fees - the only exception to this is a tenant which is late for the first time on rent - for first-timers, we typically assess the late fees and then waive them once the payment is made as an attempt to keep a good relationship but, the thing here is: 1) they don't know that late fees will be waived and 2) you should try to maintain a reasonable good relationship because after all they are in control of your investment. 

My state laws say landlord must attempt to mitigate their losses.

Attempt to find a new tenant asap.

It was not too bad (dirty carpet and sticky floors) but the smell of trash and body odor was fairly repulsive.

to make sure both your reno numbers and timeframes are realistic and that the scope is within what a newbie should be attempting.

The city eventually found out about it (when he attempted to add a fifth illegal unit, which is now a "laundry room"), and shut it down.

I want to be free to know that in 20-30 years when my body cant take the abuse of my everyday job I know I have some that will take the place of a job.

He sued me negligence, Retaliation and body injured.The timeline is as the following:Feb 26, 2019, he complained bathroom water dripping to downstair and rats crawling noise in the wall.March 3, 2019, he complained about the hot water heater issue.1.

Are you attempting to deduct certain expenses that may require Sch C income generation?

I attempted a HELOC on one of them but was turned down due to having more than 4 properties.