how do I pay online with a gift card if the total is more than the gift card

Not sure that is able to be done on the website or app but you may be able to enter the amount you have on the gift card to be paid first and then the remaining amount on a card. You can also use the gift card for any consessions food or alcohol.

Yes

You can pay with the card then if you have another use it or use a card I payed with a multiple cards so it should be easy