OpenSUSE checks everything except the part about enterprise influence. Mint maybe? I don't know much about it though.

A final thought. I know Debian has a testing branch. Anyone have any experience using that as a daily driver? Is it viable?

I've used Debian testing (bullseye at the time) before and it was a pretty pleasant experience. I like how much control I had over it compared to Ubuntu at least.

With that in mind, what distros would everyone recommend?

I like Arch and I don't have much trouble maintaining it. It's just a yay every now and then. The only issues I've had were upstream packages introducing drastic changes like when Nerd Fonts changed their naming scheme so I had to fix my ~/.Xresources manually. I use i3wm so it might not be an issue if you use some popular DE like Gnome and KDE.

Have you looked into OpenSuse's Tumbleweed or Leap? They might fit the bill, but I don't have much experience using either.

I'd recommend Mint, because, from my experience, it's pretty stable, UX is designed so terminal usage can be kept to a minimum (but you can still prioritize it if you want), support from programs is overall good, and it ditches snap. But worth noting that, if you need cutting edge features, Mint is not for you, as it seems to be the new Debian, where updates are traded off for stability.

Maiby opensuse Tumbleweed is something that might intrest you. Although it is company tied.

I'm using EndeavourOS on one PC, and Pop_OS! on another. After a bunch of distrohopping (pure arch, manjaro, Linux mint, fedora, etc.), these are the two I like the most and have decided to settle for (for now at least lol).

Your second, third and fourth points eliminate many distros such as Ubuntu. And many of the distros out there are based on Debian.

Debian isn't really stale. It is currently running kernel 6.1.10 which is not a long way from 6.1.39 (longterm, and that only came out 2 days ago). Stable gets constant updates. Testing is also generally very stable. The only thing that stops testing moving into stable is what are considered Release Critical bug count. All documented here: https://www.debian.org/doc/manuals/debian-faq/ftparchives#testing

Also while Debian 12 is LTS, it won't stop 13 from coming out and it doesn't stop you from upgrading to 13 (although you may lose LTS if they decide that 13 will not be LTS).

Debian is about as open as you can get, certainly does not infringe on your 2, 3 and 4th points.

Only other thing is what you are doing with your Linux, this might make a difference (you say daily driver, but doing what? Just office stuff, or heavy video editing, etc)

OpenMandriva recently released a rolling release version of their distro. It's a small project, but I'm personally looking at it as an alternative for Fedora.

What distro forces you in to a DE?

Mint has been pretty good for me. They didn't follow along with Ubuntu and snap everything, but if you don't want to touch anything Ubuntu there's a version based on debian directly.

My go-to distros are Pop os for better game and new hardware support, and Linux Mint if I'm wanting something a little more stable. Both have served me really well over the years.

I've been playing around with Siduction (basically Debian unstable) recently and that seems pretty decent if you want the latest and greatest.

Debian Sid fits the bill with flying colours. I'm personally sticking with Bookworm though, I enjoy stability and slower upgrades.

Another Debian Testing user here, I've been running it for I-can't-remember-how-long and genuinely can't recall the last time there was a showstopper. My use case is very standard though, no gaming or running servers or heavy development. Recently rolled up to Trixie with no issues whatsoever

MX Linux has served me well. I used Ubuntu. Get fed up of snaps quickly and changed to MX Linux.

I'm sure the arch people will be here soon to say snarky things, but...

I've used Manjaro (stable) on my desktop for about 5 years and have no reason to leave. Updates are about once a month, other than security patches to browsers that for zero-days. It's still arch at it's core, but it's less upkeep.

Maybe I don't know what I'm missing, but I feel like I'm in a pretty similar situation as you.

I like Solus. Rolling, stable, independent.

OpenSUSE Leap seems to be your best choice. It does not have the time consumption of being rolling release, but has a good release cadence. It is also an RPM distro, that should make things feel at least a little bit more familiar.

https://www.opensuse.org/#Leap

When it comes to Debian, you might find yourself getting more up-to-date software with the backports repo, particularly when it comes to the kernel. It's not a large selection of packages, but there's some useful stuff in there.

You can also use apt pinning, but that requires maintenance and makes it fairly easy to break everything.

Good idea might be to keep Timeshift on a decent schedule and if you mess something up, run through an older snapshot.

Alternatively, OpenSUSE Tumbleweed is a good rolling release that has full integration with btrfs, so mess up an update and just boot into an old snapshot. Can also choose any DE (that's in their repos, at least) on installation. It doesn't require much maintenance at all. Very unlikely to break regardless.

My go to is always linux mint. It always work every time I install.

I've been using RebornOS, which is an arch based distro. I think it fits what you want perfectly. It's a rolling release and has heaps of customisability and nothing is forced on you.