The only invalid reason given by eBay for removing a listing early is...
Note: Sellers are not permitted to cancel bids and end listings early in order to avoid selling an item that did not meet the desired sale price. This is considered to be reserve fee circumvention. Although there are legitimate reasons for ending a listing early, abuse of this option will be investigated.
So if you have a reserve, this doesn't apply. Listings can end legitimately simply by checking any of the options listed, including "The item is no longer available for sale." The seller doesn't have to explain why it isn't for sale. The explanation the seller checked will go on the record for bidders to see, after auction is ended.
Selling the item off-eBay, after listing the item, is another subject.
BTW, a non-paying winning bidder only gets kicked off ebay after the 3rd offense, and even then can be reinstated with same the ID and a bad record. I've seen it happen by appeal from the violator by pleading, "mistake, mistake, it was a mistake."
I've even seen bidders run the bids up to the reserve, to find out the reserve, or to find out the high bidders maximum bid, then cancel their bids. Nasty!