Syrup

Right, but still quite affordable compared to similar solution with Proton IMHO

Yeah, best combo for me too

You can try Frost, a web wrapper for Facebook: get in on F-Droid here.

You can also run it isolated using Shelter, another app on F-Droid, get it here.

Same for me, XFCE is light, stable and efficient. I believe that's the reason it's chosen for Debian as default DE

Dell provides XPS laptop with Ubuntu on it. It works great and Ubuntu can be replaced with other distro ( I did successfully tested Mint and now Debian 11)

Works OK but makes your connection slow as hell... Not really useful for daily usage.

You have a link?

OpenBoard with gestures? Where? Version 1.4.5 has no gestures, and it's the last one... And three is no search feature for emoji, it's in the ToDo list

Windows... With this only word you already have all the abswers

You're right for Pinta. Can't be 100% sure about Paint.NET to be fully open source but as it based on .NET it might be...

Well, GIMP is great but uneasy, not sure but Paint.NET on Windows is simpler but very user friendly and may be sufficient for your needs