in the case of spam, I haven't been spammed by nexus at all, if anything, I got like 2 emails per year form them, and that's because I had site news on. You can disable all communicate from them, or better yet, mark them as spam.
the steam downloaders work on the SteamCMD principle (or the donated file kind too for restricted games) and kemono is just an archiver.
There isn't a point for anyone to make such a tool as the website is literally FREE to use and it would be a waste of money to re-host already free content.
Honestly just suck it up and make an account, you won't be tracked down by the CIA, the FBI isnt going to come knocking at your door either just because you wanted to download Dagoth Ur loincloth replacement mod.
There is Element or Matrix or whatever the fuck that shit is called. Supposedly a better discord but the UI is so fucking bad and confusing it makes no sense.
I guess revolt and guilded are the next best options? But I am not sure how they work on Linux
I think the largest extent I went with messing around was using a Locale Emulator for a Japanese game, never had to do more than run the exe.
On Linux it's a bit of a "will it run under proton?" type game, but I'm not really thaaaaaaat bothered by it. Also fuck invasive anticheats, only shit games use it anyway.
but my DVI monitor doesn't get the love SCSI does 😔 what a society we live in....