I would pay him/her by the hour to do odd jobs like clean and landscaping. 

Consistently I was just cleaning out my basement and found my very first leases on my first duplex. 

I'm not as picky on the actual free cash flow to say it must return at least $X, but I typically get between $100-$150.I buy things stupid cheap....many folks call them "Class C" units, but we keep them clean, safe, and functional. 

I've heard it's possible, though costly, to dig up and remove all of the bad dirt, and replace it with new clean dirt.

One concern I have is the tenant turn over process and how best to handle the inspection (security deposit), cleaning, keys management, and potential showings for new tenants.

Some of the Substantial services : Cleaning of the rental portion of a property while occupied Concierge services Guest tours and outingsMeals and entertainment Transportation Other hotel-like servicesI am not familiar with your situation, but make sure you are not paying SE taxes when you dont need too. 

It needs a full interior wall repaint on the main floor and upstairs bedroom (bungalow) to clean things up.

Granted, Cambridge is very different from Lowell, but make it as easy as possible for prospective tenants.Explain how to get a parking permit if required by the city, where there is typical parking, rules for street cleaning, etc.

Rents are current paid on time according to the rent rolls, property is kept clean, everything appears well on paper, but what are you doing?

You are better off getting started with a clean slate anyway.