If you do not insure the LLC for Property Management, there are a lot of situations where you will be uncovered.  

Asking great questions, building rapport and trust with the seller, and uncovering the "why" behind the sale enables you to get past price and explain the situation as it is.

Wholesaling can evolve naturally, because you're not going to be able to take down all the deals you uncover, if you seriously go after the lead generation & deal flow. 

I would advise to explore those issues, uncover their sources, name them and deal with them in a straightforward manner.

Phrasing it that way allows you to just start a conversation and uncover their motivation, or lack thereof.

We don't know a lot about the type of mailers going out, but if we assume a blended response rate between Postcards at 0.5%, Zip at 1%, and Yellow Letters at 5-8% the I'd expect the response rate to be significantly higher. 

If your broker agrees, make sure you get it in writing to cover yourself.I won't do anything to ever risk my broker's license and although you may think it's okay, it only takes an audit of your broker's books from the association to uncover this transaction and raise red flags.

If you are growing modestly, you will still uncover the occasional value-add property. 

This had always been my intention - to get into larger properties with 1 roof, 1 driving route, 1 sprinkler system, etc, but I recently started considering the multiple 4-units to (A) increase property value (through leverage) and (B) create a path to "average-out" to a decent blended cap rate across multiple properties.The multiple 4-unit strategy would allow me to purchase 2 properties with ~30% LTV within the 1031 window to satisfy the requirements, then do a cash-out refi (almost immediately) and redeploy the rest of the capital into 2 additional properties when cap rates improved.

If everyone is sending it, then they are just blending in.