can i list an item on more than ebay at the same time. can i end listing before 7 days if no bids

[disneyshopper]

Be aware that if you list on multiple platforms, there is the possibility that you will get 2 sales at the same time.  Most sellers who do this will cancel the sale on the other platform, because cancelling a transaction on ebay causes more consequences than on other sites.

[rfmtm]

If you only have one of the item, this is never a good idea, because if it sells elsewhere and you don't cancel the ebay listing before is sells here, you have a problem and can still end up paying a fee and getting a strike on your account.

Yes, you can cancel a listing and if no bids or offers, there will be no penalty.  The END option is in the drop down menu next to the item.

[inceptions]

Since most bidding occurs at the end of the auction, it would be unwise to end it prematurely.