You'll probably do a good job researching the PM, but ask for references from current clients and ask around.Fee structure - this is where PMs can disadvantage you.

What is the disadvantage to a broker taking on someone like myself for only a handful of deals a year? 

The disadvantages, typically, are a slightly higher rate than traditional fixed- rate mortgage loans, and a larger down payment is required by lenders.

Not sure how it works in your market but bringing a buyers broker to the selling broker in my market for a commercial property would put you at a distinct disadvantage at getting it.  

I'm curious to know if I am likely to run into roadblocks or disadvantages with this strategy.Thanks for any help!

All that I see are disadvantages. 

A disadvantage of using an llc.

Persistence is a good thing, but on the other hand,  you don't want to get so attached to the idea of this house that you're willing to buy it at a disadvantage to you (like without seeing it, or if it needs more work than you predicted, etc).

Landlords operating at a distance have a very real financial disadvantage.

I also aknowlege that the purchase of both is speculative- the area these are in are always where people want to livePotential disadvantages -- taxes.