I have daily driven (a) Fedora(-based distro) ever since I started using Linux. So I’m absolutely biased towards it. However, as Fedora is a semi-rolling release distro that really likes offline updates that involves a reboot, it simply falls flat when it comes to satisfying OP’s needs. They would have a very similar experience to their current one with openSUSE Tumbleweed, the very same they actively want to get rid of.
As such, this distribution would need to be able to handle running for weeks on end without a reboot.
So, it has to be something stable (i.e. receive little to no updates) that’s capable of updating without requiring a reboot. That makes any stable distro a candidate. As such, choose either:
As I noted in the footnotes of this comment, Qubes OS is technically not a Linux distro as it’s based on Xen instead. But yeah, it’s without a doubt the gold standard when it comes to secure by default desktop operating systems; far surpassing even Kicksecure and secureblue.
As for Tails, while its amnesiac property is excellent for protection against forensics, it’s not meant as a daily driver for general computing; which was also touched upon in the aforementioned footnotes.
For this writing, I’ll focus on the OOTB experience. Furthermore, a daily driver for general use is assumed. I’ll also try to keep it (relatively) brief and concise for the sake of brevity. The tier list found below goes from worst to best.
I’d personally grant Linux Mint a position in tier 2, though perhaps others would go with tier 1 instead. As such, a step-up would be a distro from either Fedora or openSUSE.
Thanks for the clarification!
If you trust both the source and the file, then downloading by itself shouldn’t constitute a problem. Supply-chain attacks are still possible, but that’s a hard problem to solve anyways. I suppose I’d only trust Qubes OS to handle that gracefully.
For general browsing, GrapheneOS-folk would advice against Firefox(-based browsers). Instead, they’d recommend (something based on) Chromium. Personally, I do follow that advice. But I understand if you’d like to stick to Firefox(-based browsers).
Coming back to Linux Mint, I won’t go over my (personal) qualms with the security model of the distros it’s based on. But as Linux Mint offers one of the best onboarding experiences, it would be a disservice to lead you elsewhere. Become comfortable with Linux through it. And, perhaps one day, if you feel like venturing elsewhere, you can try out distros that offer better security. Thankfully, Linux Mint’s OOTB security should be sufficient until then.
As for the article, everything except for the fourth recommendation is a W. Utilizing ClamAV could be cool, but it’s based on a very naive understanding. You wouldn’t want an untrusted file on your system in the first place. Obviously, a lot more mileage[1] is possible. But one has to learn to walk before they can run 😉.
GNU-Linux hardening is useless
This opinion isn’t shared by the author in their actions, as they are known for their contributions to Whonix; both as a security researcher (by their own admission) and (are to this day accredited) as a developer.
Is this a good list?
The link definitely provides some good info. It’s better than nothing. However, it may or may not fall short based on how secure you’d like to make your system.
Anything else I should do to secure a Mint install?
What is it you’re trying to protect and from whom? Whenever the topic of security comes up, one simply can’t engage meaningfully without mentioning a threat model.
In this case, I’ll assume you’re just your average Joe. And, depending on how you engage with your system, Linux Mint might be fit from the get-go. However, if you actively engage in downloading random jank from the internet and have ‘survived’ with the help of Microsoft Defender Antivirus, then you should know that a safety net as such doesn’t exist over on this side. Sure, security through obscurity might save your ass a couple of times. But it’s inevitably a losing battle.
So, without knowing your threat model, note the following important advice that the article somehow hasn’t touched upon:
I understand where this is coming from. Buying a spec-wise similar device from say Lenovo would definitely be cheaper. Unfortunately, whether it is System76, TUXEDO or NovaCustom, we pay a premium for the fact that they’re Linux-first.