Do stores accept a copy of one's passport for VAT of should I carry my passport and leave the copy at my hotel? Can't remember what I've done in the past.

I haven't ever spent that much money so never had to try to get it, but if any one did, it would probably be specific to that store and nothing you could count on across the board. If you really want to do that, I'd suggest you take the passport with you to be on the safe side. I've had places accept a copy just as ID but I also had one place with just a different clerk working there refuse a copy one day when a different one accepted it another day (this was for something other than VAT).

No. You will have to carry the actual passport. A copy means nothing.

Thanks, that's what I thought. I just couldn't remember what I did the last time I splurged.

It depends on the store or the clerk. I've had no problem when only carrying a copy.
That being the case, however, I suppose it's probably safest to carry the original....just in case.