The complication is that, if I understand my research correctly, in Pennsylvania, according to the 2008 "Mortgage Licensing Act", no individual is allowed to issue mortgages unless they are licensed as a mortgage originator.

Hunting down another to get them to sign one can be a wild goose-chase.BASIC RULE TO A W-9:- A W-9 is never actually sent to the IRS, but is maintained by the individual who files the information return for verification purposes.

Make sure each is individually responsible for the entire rent.

Best technique to market or how do I find investors who look for other individuals to invest with them? 

Your individual circumstance may require some other action, and you should consult with your CPA or tax advisor before doing anything. 

due to yearly contribution is only $5500/individual & $11000/couple.  

When someone goes to appraise a commercial property, they take the NOI (which you can control, but lets assume its constant) and then divide that by the market cap rate to reach a market value.Yes, you can achieve different individual cap rates based on risk profiles of the property, how motivated the buyer/seller is etc, but in general, the market sets the cap rate.  

I see there being 2 options if we purchase through an LLC:1) Refi through a portfolio loan at an adjustable rate.  2) Deed to an individual member of the LLC, refinance at fixed rate financing through conventional loan, then deed back to the LLC. 

Only the owner of a property, a licensed agent, or the actual individual or entity who has a property under contract to purchase can market it.  

I am interested in starting to invest in real estate, but I'm wondering what the benefits/detriments are to purchasing under an LLC vs. purchasing as an individual.