Thanks for taking the time to post these questions & feedback!
Can you please manually check for updates and apply any that are shown as available, wait some time for the upgrade to be attempted, then post a diagnostic log here?
I think you’re right about that. It’s an unfortunate situation, and not one that we have the resources to address at the moment. Indeed it would be great in future if the app were to be fixed and improved and to appear on flathub, or if other options appear.
Which device node are you using with wodim, is it /dev/sr0? You could run ls -l /dev/sr0 to see which group owns the device and add yourself to that group instead.
Yes, we’re slowly getting through that. So far we’ve done at least LibreOffice, Chromium, Rhythmbox, Cheese, and any others I forgot. We’ll continue this migration as resources permit. Most of the remaining apps do present some challenges like not being available on Flathub (like Brasero) or requiring careful migration of user data (e.g. if we move from the preinstalled Shotwell to the Flathub version, we don’t want users suddenly to lose their photo database). There’s some discussion here: Apps that have flatpaks