hello,
by using the editor there’s one tiny thing that I miss (or rather, my OCD misses) from UDK: Shift+N (unselect all actors)
what I tend to do to “unselect” everything is end up selecting the skybox, but I’m still paranoid about it 
Hello, Chosker!
I didn’t use UDK, but the Escape key should deselect all actors in UE4. I hope that’s close enough for your OCD! 
The console command to do this is “select none” so you can create a custom key binding via the config files to accomplish this as well. I’ve made a note that we should expand our keybinding menus to make this much simpler as well! 
both solutions seem good enough, thank you 