Typically xdg-ninja will tell you how to set things up so as many dot files and directories as possible end up in the correct xdg location instead of cluttering up the top level of your home directory.

NetworkManager (network interface/connection management)

Pretty sure you mean systemd-networkd here. I find systemd-networkd to be very nice for headless systems, but NetworkManager seems to be a better fit for desktops because of the integrations it has available with KDE/Gnome/system tray

steamtinkerlaunch makes running Skyrim with ModOrganizer2 very simple. Other external programs will probably still be tricky though

Ubuntu has significant differences from Debian so it wouldn’t make much sense to be able to install it as a “flavor” of Debian. However, *Ubuntu are pretty much already metapackages on top of regular Ubuntu. So instead of having different installers for each one, you could just make it an option during install and provide an easy means to add/switch other options later

Relatedly, pretty sure most autotypers don’t work. I know that keepassxc can’t do autotype in wayland