@NeilSmithline How much I do love that 3D cube, installing a separate application with a ton of (unwanted) features seems overkill to me, especially when it costs money. (+ I don't directly see how it would solve my problem from what it offers)

I have certain spaces designated for certain usages. Sometimes I like to put other spaces I use more close to them, or maybe put a space somewhere further done if I want to rest a project for a while but come back to it's window configuration/app state. The mouse method is quite cumbersome for this and additionally error prone. Furthermore, I don't find it preferable to remember the content of my spaces in an exact manner, so I would rather not engage with the number muscle memory but simply switch right/left with the arrow keys between related tasks. Other personal workflow reasons apply too

While the title asks for something quite general, I'm also satisfied with a more simple solution that swaps a spaces with the space next to it.

This would be so great if it would not beep on almost every click.

I'm not sure if this of any help. While it might work for some, if you're like the OP and have a minimum of 5 desktop open, you'll probably have multiple finder windows, some which not relevant for the current space at all.

10.12.4 doesn't let me do this for some reason even when I'm logged in as root and prefix cp/mv/whatever with "sudo". Does anyone know what would be a good way to replace it? If it's safe, it would also be convenient if I could store the copy in the same folder as the original.

Thanks, that seemed to work. It's still pastes relatively slow, but at least it's doable.

I'm actually on the nightly builds, but I guess I will try out that version

Can anyone elaborate on the down vote? Not the right place or not an interesting enough question?

Not sure if this works for El Captain anymore, I can't find anything at least. I cd'd into volumes and did a ls -a (which shows all files, so including the hidden ones, in a directory) which gave nothing, tried this in both recovery and normal boot mode. Did the same thing for the root volume.