There isn't much you can do about links to your site, except ask that they be taken off or sue them. The latter isn't good business. Section 8 issues aren't either, but I don't believe you'd face huge risks in this arena.
If the Realtor has links to all mortgage lenders, again there is minimal risk of criticism that would cause me concern. If it is there because they expect more business because they advertise for you, you venture deeper into this territory.
My personal opinion is that if it is questioned by someone with authority, it would be done such that you'd be given an opportunity to correct the gray area issue before suffering any consequences. I see minimal risk unless you made an issue of it, refusing to correct the situation. That is more applicable to the other question than someone linking to you. Again, I wouldn't sweat it unless you really do not want the link and they really do expect kickbacks.
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AndyZ CRCM
My opinions are not necessarily my employers.
R+R-R=R+R
Rules and Regs minus Relationships equals Resentment and Rebellion. John Maxwell