Is there any authorization from Mastercard? Who authorizes the issue of such cards?
How do these cards pass AVS?
It's modeled as a corporate sub-account. Keep in mind that it's a Maestro card - primarily a European variation of the MasterCard brand. Not everyone will accept it at point-of-sale (see the Maestro card site for a list of vendors that accept it). It's primarily an ATM card with some vendors that will accept it at point-of-sale. For those that do, you can put any name and address in that you like - welcome to the differences in European and American snooping on end users. The US has fallen quite a bit behind in the realm of respect for personal financial privacy.
Yes, it is authorized by MasterCard. There have to be limits on the account balances (in this case $10K), and there are other restrictions required at the setup. You won't find a US bank to offer these, so you're working with primarily European and/or Caribbean banks using the MC system.
These are not unique cards - you can find them around. However, the price points of these cards are low to start. See the above links for other examples and note the price differences.