No one has mentioned anything about this problem on the forum. Over the years some users have commented about being restricted by a seller, and assumed it had something to do with AS, or with sniping, but none of them (that I remember) persisted in the claim and typically stop discussing the issue after they read a suggestion to contact the seller for an explanation, which leads one (me) to believe it had nothing to do with AS, or with sniping.
If ebay was doing something such as you’re suggesting, I would think there own forums would COME ALIVE with threads full of complaints.
I just don’t see the motivation for them to implement something like this. If is it some form of random punishment for sniping, then they would (and they know it) be exposing themselves to a lawsuit. I just don’t see it.
As far as a separate ID just for bidding/sniping, I think that’s a safeguard every seller should do. I wouldn’t want some other seller to be able to leverage extra cooperation from me by holding my seller-feedback ransom.