I've searched but didn't really find anything concerning the editor and directX. Is the SDKK editor directX 9 only? If so, why? Can it be updated to DirectX 11 or 12? Also is the editor Unreal 3 or Unreal 4 engine? I'd like to get into map making and have done it in the past ( a long time ago ) so I am curious about these questions. Thanks in advance for any comments and replies.

Don't know if you can force it into Dx11 by using the "-dx11" launch line in a shortcut. You could try this by going to: \Steam\steamapps\common\TOXIKK\Binaries\Win64 and making a shortcut of "UDK.exe" and adding "editor -dx11" in the target line.
The editor is UE3/UDK