My lots are where they're planning a 28,000sqf grocery store.

How or where are you storing extra materials left over after a rehab.

I have the opportunity to buy a 2 stores, 3 rooms and 2 bathrooms townhome for $160k.

Online forms for tenants, income and expense tracking, auto add late fees (or other charges you may have), rent collection, integration with other applications, ability to store documents, etc.   

As a starting guide for markets, here's an older BP blog that has some basic considerations:  https://www.biggerpockets.com/blog/2012/12/22/out-of-state-real-estate-investing/I'd also highly suggest David Greene's book on Long-Distance Real Estate Investing: https://www.biggerpockets.com/store

For example to become a licensed broker where I operate (Ohio) you need to go through government background checks, have worked in real estate as a sales agent under another broker for at least 2 years, have a college degree, have a physical store front with office hours, have done at least 40 transactions and much more that I can't think of off the top of my head right now.

Trisodium Phosphate (TSP) that you buy at the big box stores will work.

It's not in a bad spot... close to a grocery store in the back of a suburb a little ways away from a clean river, fairly scenic area. 

I found out he was bringing in big black bags filled with garbage every night when he’d come home and storing them in his room.

Just a few blocks West of the 405 and one block North of  the 10 freeways and inside the new Metro-Rail 1/2 mile radius of the special incentive development rules to encourage more units for housing that allow new construction to have "special" or "liberal" allowances of set-backs, more height up to 5 stores where 4 were the max just prior.