Our tenet called and said the garbage disposal was not functioning.  

Landlord is not obligated to replace these items, assuming they are still functional.

Properly functioning sewer lines don't need "maintenance"...My guess is, it's either an old clay pipe with tree root problems (in which case they should replace it, or remove the tree), or it's improperly installed / runs uphill (in which case, it needs replaced). 

Besides a firm education on real estate basics, I would suggest becoming an expert in a niche, whether that niche being a neighborhood, property type, or functional area like probate, bankruptcy, etc.

Data inside the Blockchain is protected by a cryptographic hash function making it immutable.The systems and the critical parties involved would be able to communicate in real time.

Sometimes the tenant will fight even though the house is more legitimately functional but you would cut your odds way down with decent maintenance work. 

A license is required if there is a way for the buyer to vacate an option-to-purchase contract, and the individual begins performing real estate functions such as marketing the subject property, bringing in a buyer, etc.

Spent ~50,000 to add a more functional bathroom and full kitchen to convert the space to a more residential layout.

After looking over the things you said you'll be doing, I wouldn't roll all of them into one fee, because they cross lines of functions. 

Step 2: I would use the search function to see the answers given others who had asked the same question.Step 3: I would get ready for my inbox to explode with connection requests from people who have something to sell you.