The 1980s called. They want their news back.
I love it as well, just thought alt or indie was too much a stretch for this one.
I agree. I used Debian for a very long time but found a move to Sid for fresh packages to be a frustrating experience so I just moved to an ubu based system.
Can the song really be called "indy" or "alt" if it topped the Billboard Modern Rock Tracks chart?
Neither. Only fortune cookies can steer you along the true path.
When they say base, they're talking about the distro it's built off of(Debian, arch, slack, fedora, Ubuntu, etc.). As an example, Mint is built on the Ubuntu base, Bunsen is built on Debian, etc. These are often called flavors as they're not considered distros but rather something built on top of a distro.
The major visible differences in distros are the package managers and tools provided for it but they also have different goals. Debian aims for rock solid stability, fedora puts FOSS first, Arch is designed to take up your free time by making you build everything from scratch and pointing you to a wiki when you're stuck (I kid).
The flavors then customize the experience, usually muddying the distro goals in the process. For instance, someone might take a fedora base then pack it full of proprietary software and release it.
I wouldn't say what you use is irrelevant but you can truly make every base look and perform the same if you do some work. People that don't like a particular base usually don't want to do that work, they want to use it. I'm one of those people. Where I used to love tinkering in Linux, now I just want to get it up and running so I can do my stuff on it.
You can easily fine tune what requires a password in Linux by editing the /etc/sudoers file.
Debian stable will always prioritize stability and provide you older versions of applications. Even Debian Sid(their testing/rolling release version) gives you less than bleeding edge versions of apps. You can always install your own versions by downloading from provider or building yourself but if you're wanting more current software, I'd consider another flavor of linux.
You can always install other themes, icons, etc. to get the look you want, Debian is just the underpinnings of the desktop. Using XFCE there is no different than using it in another distro.
The size difference is because of preinstalled applications, as you suspected. Some call it bloat, others just understand that Ubuntu is trying to cater to "set it and forget it" user.
Can I ask what you consider "spamming ads" to be? That could be relevant to suggesting alternatives.
If you haven't already, I would consider cross-posting to the privacy community. I imagine you might get some useful critique from them. I'll definitely try it just for fun. I'm pretty sure I wouldn't replace my connect app, but I'd love to at least try it