

Do it.
There’s really not much that can end badly, someone gets in your network (unlikely anyone even knows it exists)? reformat all your shit. Just by knowing what a DMZ is you are already more qualified than half the people I’ve met self hosting
do you run a business out of your house? do you run a bunch of peoples personal info? does anyone else? If you answered no to all of these then there really isn’t much that can “go wrong” you can just unplug your shit.
hosting email also isn’t that big of a deal but your home ISP will block port 25, you need to have a “business” one for them to unblock it and even then sometimes have to directly request it. Things like mailcow docker make it dead easy.
and yea as the other guy said always update your stuff
flatpak does indeed deduplicate. The stuff is updated to whatever is required as a dependency to whatever programs are installed. And versions are shared between applications when versions match as well…
So I am guessing it is just like flatpak