Linux

I would create another couple of efi partitions, just to confuse attackers more

On a more serious note, as others have said, you'll probably burn through these weird storage limitations quickly.

Also, what do you mean by "sensitive matters" on Mint? Because almost any way you spin it, I feel like it's not a great idea:

• If you're talking professional, confidential work with clients, keeping it on the same device where you do anything personal sounds like a terrible idea, and it's probably worth it to shell out for a dedicated device just for this.
• If it's more personal things like government documents, medical records, and other things I'll neglect to name here, running a separate operating system just for those just feels like unnecessary paranoia and will cause you unnecessary trouble. If you're careful, it shouldn't be a problem - the major browsers prevent file access through protections against cross-site scripting.

Also, as I said in another comment here, please upgrade that drive before you put a lot of data on it. If you don't and you run out of storage later (a near-certainty on 256GB), you'll have to go through the effort of getting everything copied, which may include equipment purchases and several hours of your time when you could jut do it right now while your important files are still small enough to fit on a flash drive right now. Save yourself the future trouble.

Anyhow, I wish you happy Linux usage.

• You don't need multiple EFI system partitions! That's why Mint and OpenSUSE don't show up in each other's boot menu (or at least that's the first step, depending on your bootloader). The intention with the ESP is you put all EFI executables for dual-booting (and triple- and beyond) in there.
• Swap partition is fine anywhere. But as an aside, you can also just use a swapfile. Makes it easy to change the size dynamically. https://wiki.archlinux.org/title/Swap#Swap_file
• /dev/nvme0n1p6 I'd wonder why that's needed. /boot on /dev/nvme0n1p10 too, that's not strictly necessary.

None are game-breaking! You can just note these down for next time you have the itch to tinker.

Why keep the windows partition if you don't use it?

nuke it 😎

Is there any reason? You're effectively wasting half the drive by using that space for OSes you almost never use.

If you ever happen to need Windows, which I don't see happening as you yourself can't imagine an actual use case, you can just go to the library or borrow a friend's computer or maybe use your phone.

As for Mint, do you just have it to experiment with? If you're just trying to try out other distros, a virtual machine or even live USBs are much easier ways to quickly try out new systems without having to clear actual partitions.

If you had much more storage then sure, waste some of it, but you're really gonna be missing that 120gb if you use your computer for... basically anything.

The order of the partitions basically doesn't matter at this point -- I think having a boot partition first used to be important for MBR schemes but I'm pretty sure in the UEFI era you can have them in whatever order. As others have mentioned, you could combine your EFI partitions, but doing so to an already installed system is slightly complex. You also could shrink some of your EFI and boot partitions, I'm not sure of the recommended sizes off the top of my head but I think they could be smaller. On the other hand, your swap partition should probably be bigger -- making it the same size as your RAM is a good rule of thumb and will enable hibernation (I think).

I really don't think 60 GB will be enough for daily use unless you have your home folder on a separate drive, which it doesn't seem is the case from your screenshot.

I have mine on a separate drive and my system partition (150 GB) is half-full. Is there a reason for your 25 GB per Linux installation rule?

Is the swap space unencrypted? If so it could potentially weaken overall system encryption