Continued to install Telegram Desktop as root. (Remarks: Telegram Desktop is working fine.)
Googled and understand that
Flatpak’s update is done automatically by the Flatpak’s updater service that runs 10 minutes after every boot.
and update of Flatpak’s app also can be done using the command in root #flatpak update org.telegram.desktop
Question: Is the above understanding of Flatpak’s update mechanism correct, meaning Flatpak will automatically update the app if there is a newer version?
While researching for the above, I deleted telegram desktop app and found out that I can install it as a normal user.
Question: Should installation of Flatpak’s app (eg most user app like Telegram, Gimp etc) be done in root or as normal user?
Question: Is the above understanding of Flatpak’s update mechanism correct, meaning Flatpak will automatically update the app if there is a newer version?
Usually your software store (GNOME Software, KDE Discover, etc…) can automatically update your Flatpaks instead.
Question: Should installation of Flatpak’s app (eg most user app like Telegram, Gimp etc) be done in root or as normal user?
It is advised to install as a normal user. By default Flatpak will make the app available to all users in the system, but you can also use the flatpak --user install <app-id> option to install an app just for the current user. See Using Flatpak - Flatpak documentation
I tend to run flatpak update regularly, out of habit. I thought that if I didn’t mind what was happening I’d automate it with flatpak update -y (Flatpak Command Reference - Flatpak documentation).