How to purge old Openshot files?

I want a fresh install of Openshot using its latest Linux(64-bit AppImage) file on a machine that had previously installed Openshot via apt, snap and flatpak. I have purged all its old installations. I have even purged flatpak. However, I still found Openshot files on this machine and its thumbnail appears in the Ubuntu 22.04 applications grid.

$ sudo apt list | grep openshotWARNING: apt does not have a stable CLI interface. Use with caution in scripts.libopenshot-audio-dev/jammy 0.2.0+dfsg1-4 amd64libopenshot-audio-doc/jammy,jammy 0.2.0+dfsg1-4 alllibopenshot-audio-test-sound/jammy 0.2.0+dfsg1-4 amd64libopenshot-audio7/jammy 0.2.0+dfsg1-4 amd64libopenshot-dev/jammy 0.2.5+dfsg1-6build2 amd64libopenshot-doc/jammy,jammy 0.2.5+dfsg1-6build2 alllibopenshot19/jammy 0.2.5+dfsg1-6build2 amd64openshot-qt-doc/jammy,jammy 2.5.1+dfsg1-2 allopenshot-qt/jammy,jammy 2.5.1+dfsg1-2 allpython3-openshot/jammy 0.2.5+dfsg1-6build2 amd64$ sudo apt purge openshotReading package lists... DoneBuilding dependency tree... DoneReading state information... DonePackage 'openshot' is not installed, so not removedThe following packages were automatically installed and are no longer required:  libappstream-glib8 libmalcontent-0-0 libostree-1-1Use 'sudo apt autoremove' to remove them.0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.$ sudo apt purge openshot-qtReading package lists... DoneBuilding dependency tree... DoneReading state information... DonePackage 'openshot-qt' is not installed, so not removedThe following packages were automatically installed and are no longer required:  libappstream-glib8 libmalcontent-0-0 libostree-1-1Use 'sudo apt autoremove' to remove them.0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.$ dpkg -l | grep openshot$ flatpakbash: /usr/bin/flatpak: No such file or directory

However, according to Nautilus, many residual files are in the /var/lib/flatpak/app directory.

Also, the Openshot thumbnail continues to exist in the Applications grid

but folders ~/.local/share/applications and /usr/share/applications do not contain any openshot .desktop files.

Questions:

1. Can I simply delete the folder /var/lib/flatpak/app/org.openshot.OpenShot and not cause any problem to the machine?
2. Since I have purged flatpak, can I even delete folder /var/lib/flatpak?
3. Also, how do I remove the Openshot thumbnail in the Applications grid?

Update:

I discovered the existence of a file called org.openshot.OpenShot.desktop. It's paths are:

• /var/lib/flatpak/app/org.openshot.OpenShot/x86_64/stable/a3e062afc67b6bcba4c61fffa4a9c7d4baab1fb0843f99b8f79e2497e15bc42e/export/share/applications/org.openshot.OpenShot.desktop
• /var/lib/flatpak/exports/share/applications/org.openshot.OpenShot.desktop

This terminal command removed the Openshot thumbnail from the Applications grid:

sudo rm /var/lib/flatpak/exports/share/applications/org.openshot.OpenShot.desktop