What you suggest is effectuating the transfer, as in transacting or brokering, of a security instrument. All NC laws (NC General Statutes) related to securities are spelled out in Chapter 78A. North Carolina Securities Act.
Related to your post, a transaction of a security interest in real property would be an exempt transaction, per § 78A-17. Exempt transactions, which says:
Except as otherwise provided in this Chapter, the following transactions are exempted from G.S. 78A-24 and G.S. 78A-49(d):
...
(5) Any transaction in a bond or other evidence of indebtedness secured by a lien or security interest in real or personal property, or by an agreement for the sale of real estate or chattels, if the entire security interest or agreement, together with all the bonds or other evidences of indebtedness secured thereby, is offered and sold as a unit.
Since you would be brokering these deals, and (apparently) not servicing the security instrument, Article 10, Mortgage Debt Collection and Servicing, of Chapter 45, Mortgages and Deeds of Trust, would not apply to you. Your buyer, though, should know these chapters of NC law as well as federal servicing laws.
Note that by NCGS §45-90(2) (Definitions) a NC "servicer" is defined in RESPA, the Real Estate Settlement Procedures Act, 12 U.S.C. § 2605(i). Also note that RESPA applies to federally related mortgage loans, not notes from private investors.
So, in the context of your post, I don't see any "illegal activity."
This post is not to be construed as legal advice. This post is for entertainment only.