emacs + org mode.

You can sync the notes files with any app of your choosing (OneDrive, Google Drive, Nextcloud, Syncthing).

deleted by creator

It depends on how much time you want to spend learning it and become a power user.

1. If the answer is ‘enough’, the best distros out there IMHO are Arch-based (Manjaro, EndevourOS, Arch itself). Plus the community is the best.
2. If you aim for a more ‘set and forget’ experience, I’d go for Ubuntu LTS as base with KDE. In particular, I’d go for Kubuntu LTS or KDE Neon.

If your reasonably tech-savvy and you are in for the long game, I suggest to go for n. 1: it’s a worthwhile investment.

I support what some of the people here say: don’t do a hard switch.

Install Linux in dual boot (or, if possible, use a dedicated machine) and see how it goes. You can always fallback to Windows if needed.

My 2 cents:

• Stick to one distro/DE combination, otherwise you’ll get burnt out by decision fatigue. As a beginner I suggest to stick to Ubuntu LTS as a base and KDE as a DE. These are very mature options and IMO everything you’ll ever need until you become an expert (and then you can start exploring more DEs combinations and/or use more advanced distros like Arch). My suggestions: KDE Neon or Kubuntu LTS.
• In terms of software I can suggest Kdenlive for basic video editing, DaVinci Resolve for pro video editing, REAPER as a full featured DAW, Bitwig Studio as an Ableton Live replacement. For image editing I know that GIMP 3.0 is coming and seems promising as a semi-pro alternative. These options comes with native support on Linux and many of them are professional-grade software choices.
• In terms of OneDrive, there’s no Linux client AFAIK. If you are not interested in syncing the files locally, you can use the web version, but it’s not ideal. As an alternative, you can use something like rclone to sync files to/from OneDrive, but requires some setup work.

In Linux there are already much better options than Ardour that I highly suggest to try:

• REAPER as a standard DAW and Ardour equivalent.
• Bitwig Studio for more sequencer-like worflows (alternative to Ableton Live, FL)

These are not hobbyist products, we are talking about professional level software here, so they are both paid.

In any case REAPER is usable for free if you don’t use it commercially and it’s so cheap for the value it brings that there are no excuses for not buying it.

Python.

Just remember to use pyenv for interpreter installation, version and environment management. It’s pretty straightforward that way and you have predictability.

Don’t ever manually fiddle with the system python and/or libraries or you’ll break your system. You should just rely on the package manager for that.