I didn’t vote because “none of the above” wasn’t available.
Choice of shell. Maybe add another shell in addition to bash. If this option means replacing bash with zsh, etc. then definitely not. That would be going against Unix, BSD, and Linux history from the very beginning. Anyone experienced in CLI EXPECTS bash to be there.
Choice of kernel. This could be OK, but personally I would limit it to Current kernel or LTS kernel. Maybe always install the Current kernel and offer LTS kernel as a backup. Anyone wanting a different kernel besides these two would have enough knowledge to easily install them.
Choice of browsers. This is kind of covered in Welcome.
BTRFS EndeavourOS is targeted to less experienced users wanting an easy install of Arch Linux so they can learn as they go. If so, then my opinion is I would want them to be using a bullet proof, very established file system designed for personal workstations. Namely ext4. But I might have too much of a old school stance on this. So, maybe, but a lot of inexperienced Linux users would select this simply because it’s there and not fully understand what BRTFS is. Which would increase forum traffic greatly.
LibreOffice LibreOffice is handled nicely with Welcome.
Firewall Oh brother, don’t get me started on this one. My opinion is a firewall should be installed de facto on every installation and enabled for normal PC usage. Also, correct me if I’m wrong, but ufw has not been maintained for quite some time. With the new successor to iptables coming along, that might be a problem in the future. I think firewalld which is actively maintained by a corporate distribution might be a better choice.
Bluetooth. I have never owned or used a bluetooth device, so no opinion.