A swap partition doesn't have a filesystem - it has its own partition type and doesn't contain files. The installer might create one automatically or it might not - if it asks how large it should be, a good rule of thumb is to use the same size as your RAM.
If that turns out not to be enough, you can create a swap file on a data partition later and if it's too large, you just wasted a few GB but usually that doesn't matter.
The first installer will install the bootloader automatically.
It will also create a swap partition unless you tell it not to, and all distros will use all swap partitions by default, so you don't need more than one per disk.
If you don't hibernate one distro and then boot another, sharing a swap partition isn't a problem.
There shouldn't be any significant difference between the GRUB versions that come with different distros, so the order in which you install the distros doesn't really matter.
You can't install multiple distros on one partition, so you need at least one partition per distro.
I think the easier solution would be not to use hibernation - either shut the system down properly or use suspend-to-RAM.
If everything works, the bootloader should be whichever GRUB version comes with the distro you install first and the other distros' installers should just add entries to boot them.
One thing that might matter is that if all distros use the same swap partition for hibernation, you shouldn't boot one distro after hibernating another or you might overwrite the saved RAM contents.
If you use different swap partitions or files, you probably should still avoid writing to a partition that belongs to a distro that isn't actually shut down.
I used it in a Windows 98 VM a while ago when I tried opening a large text file - apparently Notepad on 9x only supports files smaller than 64 KB.
Not quite - even in PowerShell 7 there are some features that only work on Windows and Windows only comes with PowerShell 5.1 by default.
I FIXED my CAPSLOCK KEY to FINALLY enable CRUISE CONTROL for COOL
Adapter cards for one PCIe M.2 SSD are completely passive and work on every motherboard with PCIe. If the card has multiple M.2 slots, you need either a PCIe switch on the card or a motherboard that supports PCIe bifurcation.
I upgraded an old machine that doesn't have PCIe 3.0 or M.2 slots with a Samsung 950 Pro in an adapter card and I haven't noticed any issues - the SSD only runs at PCIe 2.0 speeds, but that's fast enough for me.
Sometimes plugging a PCIe card into one slot will cause fewer or no lanes to be allocated to another slot, so you should check your motherboard's manual before buying a new card.
Typical Internet Contrarian™ logic:
Hibernation is an OS feature, so you can't disable it in the BIOS. You can either disable it in all your distros or simply not use it.