Ebay would not be declining any offers because they think a seller is bad. An offer from a seller has a limited time in which you may accept it and then it automatically ends. If another person purchases the item, then the offer will also automatically end. In some cases, a seller can cancel an offer they made. So ebay isn't doing any of this because they have suspicions about a seller. If they don't like a seller, they toss them off of the website.
Your post is somewhat confusing because on one end you sound like you are the buyer receiving offers from a seller and on the other hand you sound like you are the seller receiving notification of an offer. As a seller, one wouldn't even receive notification of an offer that was below an auto decline amount. There have also been delays where some sellers are receiving emails from ebay later than they should. A buyer is also able to cancel an offer. I always go directly to ebay and never solely rely on email notifications.
