Hello, can I use a Fandango gift card at the counter or do I have to order my tickets online?

Yes. You can use it at the concierge

Yes I'm sure you can do it either way. I used mine online ahead of time so when I get to the theater I just show the usher the receipt on my phone

Yes

Yes, but call ahead to make sure you don't have to order online first.

Yes i believe so