I don't use plasma anymore but you should check in desktoo effects or kwin scripts sections of settings. If not there I'd check the keyboard shortcut list for Super + Shift to see what is being activated by the shortcut.
I guess it's to direct more people to Microsoft 365 and Word. I hope that in reality more people will start to use LibreOffice and others.
This is supposed to be the most used operating system, recommended for its ease of use. Meanwhile you have to sign in to use a clock app. Such a shame, especially because the focus timers are actually useful.
From what I know simple editing is coming in a future update, maybe Loupe 48. I don't think there's a way right now.
Shitter is an actual app on F-droid. It's a mastodon client.
It's a security update because it adds new security vulnerabilities.