I wanna get answers from actual Linux users, how supported is UE4 on Linux, is it the same version as Windows?
I’m a Linux user! 
It is supported… But not anywhere near the windows version.
But it runs fine on Linux. With these exceptions:
Only build games for Linux! (But you can move all the data to a windows version and build it for win or Man)
No launcher
You have to build from source…
Besides that, it works fine. And is pretty much the same in all ways as the windows. But uses Opengl instead.
It works best on ubuntu 64bit.
Hope that helps!
P.S. It has problems building the lighting offline. But it works online fine.
The actual editor is the same, but currently it’s still in development and it’s buggy, they’re working on it though and it’s pretty impressive what they’ve got going.