Is there a gift shop?

Yes

Yes. It's small. Not particularly impressive but I'm certain you could find a small trinket that you could place on display somewhere, but not in a prominent spot. The Art Museum, only a quarter of a mile away has a good not great selection. If in NYC go to Rockefeller Center, the Metropolitan Museum has a store there and you can find many art collectables. But unsure if there's Rodin items.

Yep