Start by talking with banks. 

I've heard so many horror stories, and know I am bound to have some myself, but what are some things that can prevent disaster by including in your lease agreement?

High quality hotel brands are owned by investors and  triple net leased to management companies.

He wants landlord to take care of this matter by using rocks to cover the ground. 

@Michell ChaseThe main difference between W2 and 1099-R income is that you have a much easier path to qualifying as a Real Estate Professional without a W2 job.Whether or not qualifying as REP will be helpful to you is case by case. 

Found and negotiated by with local agent.

I'm trying to do BRRRR on this unit by renovating the whole bathroom, kitchen and etc.. but not sure how much it would appreciate as it's a basement unit but it has 5 bed 2 bath...

@Patrick Fricchione, You will not create any tax consequences simply by converting the use of a property. 

Apartments.com makes money by landlords paying to make their rental listings "premium" to get bumped up in search results.

It scrapes your lists using data points from the entire history of past transactions and ranks properties by their likelihood to sell.https://www.dataflik.com/