Is there a way to see all user wishlists that contain a specific item? If I had an item I wanted to gift, but didn't have a particular user in mind to gift it to (perhaps I've received a duplicate from a quest reward, RE, etc.) I'd like to be able to see a list of users that have said item on a wishlist, if that's possible?

Yes. Personal->wishlist, then look at the top left of the page for the Search tab.

There is a tick box to limit it to your friends only, or just search everyone.

Awesome, thank you so much!