As of May, 2021 I did not face serious problems to setup my new mac mini M1 as development environemt.

I did not try to run docker with firewall enabled though - firewall systems on the system they are supposed to protect are snake-oil, they do not protect anything. The firewall must be independent from the systems it is protecting. I know that both macOS and Windows come with OS-integrated firewalls. It is bullshit nevertheless.

Beside that I was able to setup a Flutter and Docker development environment with almost no issues. Cocoapods, needed by Flutter for iOS devices, is still not fully armed. There is an easy workaround for that, which I managed to lookup on the internet (run terminal in rosetta mode, install cocoapods). Android Studio runs on Rosetta and does not have working arm-Emulators on the release-channel yet. But using the beta-version resolved this. Homebrew had no issues at all. I am not at all into Python programming, but every Linux distribution nowadays comes with both versions of python. What macOS does is normal. Update of macOS from 11.3 to 11.3.1: no issues.

And I am amazed how well Rosetta 2 performs on software not yet "armed": I can even run games from Steam like "Surviving Mars" or EU4 without issues. Fun fact: Surviving Mars has a well-known graphic bug on Intel Macs.

It doesn't show that bug on the mac mini M1.