Cześć,

We're also suffering from shitty politics, the current allegedly right-wing governing party — PiS, Prawo i Sprawiedliwość or Law and Justice — has suspiciously a lot in common with PZPR, Polish United Worker's Party, and has got nothing to do with what one would think that they should be standing for: law and justice. I hope we will succeed to get rid of their puppet of a president this year because parliamentary elections are over three years from now.

1. They don't differ much in this regard, the biggest difference between bigger (and mid-sized) cities and smaller ones is that the latter usually don't have any Bitcoin ATMs or Bitcoin/blockchain/cryptocurrency-related meetups if that's your thing.
2. Warsaw and Kraków are the biggest cities (still tiny compared to a megacity such as Moscow) and the most cosmopolitan ones (nowhere near as much compared to places like Paris or London, though), although other major cities such as Tricity, Łódź, Wrocław and Poznań are also OK.
3. Depends on the bank, some don't deal with foreigners (especially non-EU) and/or non-residents, some do. Should you decide to move here legally getting a bank account wouldn't be a problem. Selling/buying cryptocurrencies for private purpose isn't usually a problem, but things get trickier if you want to sell or buy cryptocurrencies in the course of running a business, depending on the nature of the business many banks can be picky.
4. Generally speaking, nowadays it's very safe for everyone, cryptopeople or not.