In this case, is it legal for me to act in the capacity of a finder and charge a finder's fee considering he negotiates the deal himself?  

You are paying them a monthly fee & insurance so they are more opt to consider you pay them to hang your license while learning the ropes.  

I was the only bidder & I purchased it for $211,331 using a HML with 25% down, 12% rate, 11mo term, with a $225 transaction fee and a $200 payoff fee payable at the end.

Even if they have a full time job they may be willing/interested in going the extra mile if you offer a fee for each mobile home they find/fix/get ready/rent, etc.  

@Brian PulaskiSorry for the late response but they charge a one time fee of $1147 to become a student.

Also, does anyone have a recommendation for the best wiget for accepting fees and rental payments?

But not everyone will be nice and there will come a time when you will have to be assertive and firm and will have to ask them to leave, and that is with applicants who wonder why you charge so much for rent and move in fees.

Refinancing usually comes with a lot of fees- they don't really talk about that so much-  so you want to make sure you get your money's worth when you do refinance!

Most benefit from not needing an HOA fee.

You would still need to cover your finance fee but just another option to consider...