PlexCard Visa : Would it be legal all around the world? Recently, Plexcoin is to come up in the market with very promising future. Directly, citing from their website, the features include 

In comparison to Bitcoin (45 minutes), the transactions (deposit, withdrawal, purchase, sale, transfer) of PlexCoin are confirmed faster (30 seconds) and they have increased storage efficiency. 

and

With PlexCoin, you will be able to undertake regular transactions and spend money with your PlexCard VISA© anywhere around the world. You will also have the option to send or receive funds from anyone, in a totally private way.

Will the VISA card be legally accepted around the world ? 

and 

How can they achieve(claim) to have such fast transaction confirmation time ?
VISA and MasterCard cards are issued by banks all over the world, that have a valid license. It's not the first time we see cryptocurrency based VISA card. Those cards can be used in every shop (online or physical) that accepts VISA cards.

If this PlexCard VISA card is issued by a bank that has a valid license to issue VISA cards, then the card will be legally accepted wherever VISA cards are accepted.

As for the second question (fast transaction confirmation time), I don't know about PlexCoin but there are other coins with near instant confirmation times, that are using techniques like faster block time and/or MasterNodes.