Alternatively, my more specific is Malden and Everett which has direct access to trains and buses and you can find 2 families for the same price range and an occasional three family with work needed.

I like the idea of a 4 plex I rent out 3 units and use the 4th for myself/family/friends maybe occasionally vacation rental. 

One full time guy can handle 30 with occasional outside help.

I like your participation mortgage idea, as well as your bloat the note mention. 

I'm no better at handling this stuff than you are; I need someone to occasionally give me the same advice. 

(Having said that, I have occasionally lent 100% but the circumstances are unusual and rare, and never with a beginner. 

I know the MLS posts an occasional lot but they are often too overpriced to used by a flipper.

For those of you who get lists from public sources, free or paid, they obviously are bloated with non qualifying leads that need to be trimmed like banks, LLC's, recently sold, etc.Beyond this I'm not 100% sure what I should be keeping on the list and what I should be eliminating.What are some traits you guys look for when filtering you lead lists?

But I reckon those same "rich" folk do occasionally sell/trade-up. ie. not mantra-obeying robots!

Several of my mobiles have different rents that were grandfathered in, so that helps, but several are on the same rent and occasionally someone will forget their printed deposit slip and just go to the bank and hand write one out and not put the unit number on.