Questions[purge](ubuntu)

Some time ago I installed Brave but I didn't like it, so I removed it with sudo apt-get remove --purge brave-browser. After some time I had to reinstall it because I needed a Chromium-based browser. As soon as I opened it it asked be to redeem my old BATs, so I deduce that apt-get left something in my system.

Now I don't need Brave anymore and I'm wondering how to remove it completely. I would use sudo apt-get remove --purge brave-browser once more but it looks like it doesn't really remove everything - what command should I use instead?

I purged firefox(*) and deleted /etc/firefox and /usr/lib/firefox, the whole .cache thing and so on as already mentioned in Removing Firefox in Ubuntu with all add-ons like it never existed

After all, I still find "Firefox Web Browser" in All Application and even firefox --version shows me (even after reboot)

Mozilla Firefox 72.0.1.

The command type firefox says

firefox is /snap/bin/firefox

What should I do to completely get rid of it?

Do I break anything if I

sudo apt-get purge apport

I have my secret business plan for world domination and who knows what's in a core dump?

I've seen Ubuntu (in particular dconf) recreate config settings. I know how to disable it but can't trust it to remain disabled. Hence my question.

Yea Yea I know know my different distro ... but I'd like to use Ubuntu if I can.

Possible Duplicate:
What is the correct way to completely remove an application?

I installed UltraEditor (uex package) from a source I can't remember. Later I purged the installation with:

aptitude purge uex

The application disappeared but its name still appears when I type Alt-F2, as one of the installed applications. Is there a way to prevent this from happening?

I've installed a number of packages from PPAs, and I would like to revert to official versions now. Many of the PPAs no longer exist in /etc/apt/sources.list.d, so ppa-purge will not work on them.

What is the most straight-forward way for that?