I'm planning to target mom and pop owners with 4-20 units in B- and C areas.

Bad tenants are going to complain, whether the property is owned by mom and pop, or by Invitation Homes. 

My experience is that most parks where the majority of homes are park-owned are mom & pop operators who live close by and do the repairs themselves.

The new casino you speak of is going up in Everett not Medford.The best time to buy was a few years ago before the casino received their building permit but there a couple of deals that pop up every now and then.

If a client NEEDS something that's a different story and we can talk about timing that deduction in a year where their income may "pop" into another bracket.

Once you buy it and put a renter in it, you might flip out because you won't get the Smith's  home-owner/primary-residence discount and your property taxes can pop up 2x, 3x or some other amount depending on where you buy. 

Looks more feasible than popping the top and building up. 

Anyway, I have been looking around the area and there have been a number of AirBnB's popping up.

This won't work that well for larger complexes but the smaller mom and pop ones would work great I would think.

Unless you can get a house with a triplex in the backyard (I just saw one pop up in central for Miami for about $850k).