Probably yeah. Unless they wish to block entire IP ranges from their servers.
I wonder if this will finally make third-party app stores mainstream. On the other hand, signal isn't on F-droid either as it was moxie's pet peeve. But now that he's gone perhaps they'll reconsider in light of this.
Not really. Merchants are the one who eat the chargebck costs plus the $20 fee for processing it that VISA/MC charge them. That's just pure utter bullshit.
Shops aren't required to take the old local currencies anymore, but they can still be swapped.
Here for instances the information if the German Bundesbank, where you can still swap with the official rate of 1.95583 DM/€.
https://www.bundesbank.de/de/aufgaben/bargeld/dm-banknoten-u...
(Currently there is a restriction of in person service due to corona, but if you trust mail it works, else you have to wait for that Corona restriction to be lifted)