YT plugin for Kodi is quite decent. Have it daily in use, no issues so far.
It’s trillan you are talking about. I am old too :D
Not as powerful as Tasker, but for some basic automation tasks PhoneProfilesPlus is a good alternative.
Using Argon NEO and quite like it. In my case it was important to have the ability to use a HAT (HiFiBerry).
Not sure, maybe “diagramming”. Btw there is a good alternative to draw.io for self-hosting called Excalidraw. Very easy to set up with docker.