You can use a Bolt card in 2 ways, either, as you say, pre-load it with Sats to gift. Or you can link it to your CoinCorner account and spend your balance on the exchange.

Yes, you can spend it anywhere that takes Bitcoin, either with a Bitcoin PoS terminal or a wallet that supports NFC payments.

But it is Bitcoin only, so you can't use it as a Visa / Mastercard alternative.

For Visa / Mastercard payments I use several options, but the easiest is Revolut, which apart from having a regular debit card, also has a Crypto debit card which will convert your Bitcoin on the fly for fiat as you tap it at a regular VISA / Mastercard transaction by setting it up in Apple or Android pay.

BTW: This is a Bitcoin only POS terminal I used at nostr:npub1kwnqcmc698gyvjngr724fhl3ntxsystyp6mr6muxh372q6vkln7sqjttzv earlier this year in Bedford.