Yes to credit cards and a souvenir shop
They do accept credit/debit cards, and there is a small souvenir shop, not a lot to choose from but you can probably find a couple little keep sakes.
In these times cards are better accepted than cash. I've to places that don't accept bills because of covid so you should be fine
Yes they do, like most places these days cash is not king
Yes, they do accept cards.
You can buy souvenirs in the visitor center. Not sure what payments they accept, but I would guess they accept credit and debit cards. It did not look like a cash only type of store when we were there.
Thanks! Your answer is awaiting moderation.