Syrup

The kicksecure documentation is well written. Go here for distro-morphing of Debian 12, step by step things to do are pretty explicit and you can even copy the command lines if you think you'll make a mistake...

You have a link?

This is the best choice IMHO. You have a rock solid OS (Debian) and all possible taken measures to harden it with Kicksecure patch.

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

TrackerControl is quite similar to NetGuard, but I find more user friendly and you have all features you need. Get the full version from F-Droid or from their Website.

For Nebulo, you can get it here, or F-droid, but the website gives you all useful info you need to know.

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

Ans there's even no Chinese brands... Will be even much worse!

I do have TrackerConrrol + Nebulo, works like a charm

Agree to that, especially for video cards and Wi-Fi. These two can be hard to deal with... If your laptop is Wi-Fi only and you don't have a USB/Ethernet adaptor you may not be able to connect to the net at all