im currently dual booting endevouros with windows, and i have a lot of free/unpartitioned space on my drive. can i install another linux distro alongside endevour and windows? i have a separate home partition as well. do i only keep one linux/grub boot partition? im not too scared of nuking everything but id obv rather not. thanks!
Gparted should help you manage your partitions. Be very careful to pick the right partition to format. Also, Windows is known to sometimes mess up dualboots, it thinks it is the only OS.
I would never ever recommend not updating windows, but if it is maybe just a dedicated gaming OS and you don't use it for internet browsing or anything else, you might be able to get away with it.
My usual setup is two distros, sometimes also Windows. I use one home partition, one swap partition, one EFI partition (Windows creates one in EFI mode) and each OS its own root partition.
Some people won't recommend sharing a home partition, but it has worked for me for a long time now. Some years ago I'd have an additional data partition, with symlinks from each home folder of each distro for Videos, Documents, Images, etc. Each distro was contained, even home, in the root partition.
Also, you can have several bootloaders in the EFI partition as long as you don't wipe/format it. Usually, you can choose which one to use in the firmware settings.
You can. Be aware that using one home partition for numerous distros is not recommended because of config files conflict. You can however symlink between home partitions.
If you're not seeking virtualisation as an option, then I'd recommend the second distro for minimal Arch/Artix/Gentoo/Void/Alpine setup and learn to configure Sway or DWL as your WM.
Depending on what's your usecase, or what you want to achieve, running different distros on different virtual machines may be the best solution for you.