However, I think a great idea for some BiggerPockets videos would be showing an actual deal happening in progress from Josh, Brandon or others.

Once an offer is signed in massachusetts by both parties it is considered an enforceable contract.This serves as better proof the seller actually was delivered the offer and read through it.

I was thinking multi as the more doors the better to help pay.

Contract is not bidding until both parties sign AND IT IS DELIVERED!

Heck, you're not even a party to the lease option agreement between the seller and the buyer after you assign, unless you structure a sandwich lease option instead of assigning).

Investors normally use the term only when referring to multi-residential or commercial properties.

Are you talking about a large multi family?

If landlording has become a chore for them they might be willing to do a deal with you that is favorable for all parties.

This is not the same process as a SFR purchase, where the buyer obtains a letter of qualification from a dubious mortgage broker; this is a very intensive evaluation.That being said, nothing is to stop any interested party, qualified or not from making an unsolicited offer.  

I currently own 2 multi-family properties in the Sacramento area and am actively looking for my next buy and hold deal.