If I do not have a receipt but have a Norstroms sticker on the item, can I return it for store credit at a Nordstrom's Rack store??

U should be able to return the item for store credit if the tags r still on the item. But the original amount u paid may not be the amount that shows up n the system now-it might be less. Good luck

Probably not, because the item could be stolen for all the company knows.

With the credit card wich you paid with yes

No. You must carry a receipt for return & get store credit.