Hi Mike,
If I understand what you’re saying, you want to work on the shop computer, but keep the records on the main computer. If you don’t need the eBay notifications on the shop computer, you can disable it on that machine. On the shop machine go to the manage agent icon and you should see a list of your computers. Then you can select a checkmark (on) for Main and deselect the Shop.
The other issue of deleting the imported items on the shop computer is a bit trickier – the concern is accidentally deleting the Main copies when the Shop backup is loaded because both copies of 6B want to be the same. At least that would be my concern, not sure if it’s valid or not. Maybe set up a custom view so you don’t have to wade through them until that’s figured out?
Hope this helps you!