I will attempt to hack out Ctrl+W; Ctrl+F4 is actually a standard, but seeing as there are multiple standards it's wise for me to try and support both. Also, middle-mouse-wheel clicking removes tabs as well.
@DaVince: You need to have engine.exe and config.exe in the folder you specify. I can't replicate your behavior, because it should just work! I'll wait and see if more people have that issue, because I just can't see it happen unless you don't have engine.exe and config.exe directly in the folder.
Also... You were able to write in config.exe, but not open it? I wonder if there are certain privilege rights blocking your access? You are on Windows, did you try turning off the stupid UAC rules?
DaVince, I think I see it now. You wanted to open the config and engine without a project loaded, right? I have turned these on, the old sphere editor didn't allow you to run either one without a project open. Anyways, I still don't know how you are getting the 'sphere folder' dialog to not fill in the editor and config! I don't know where to begin... But I'll look into it.
That's the old-style folder selection dialog. Most new apps I've seen use a dialog similar to the file selection box (so you can paste a path), so it's probably just a matter of calling the correct API.
Now all it needs is the ability to change the script editor font and tab size and I'll use it exclusively...
Then you should be using an OpenFileDialog instead of a FolderBrowserDialog anyway!
Also, a bug (or maybe just an annoying "feature" ) I found: Running the project collapses all folders in the project viewer, every single time. VERY annoying. I swear there was another bug I found, but I can't remember what it was now... oh that's right, you can't open a file from the project explorer by pressing Enter, it just dings at you instead.
Oh, and maybe add an option to change the font for the project tree? Again, the default one is too small on my 1920x1080 laptop display. Speaking of which, thanks for changing the default for the script editor from Courier New to Consolas, the latter is a much nicer font for programming.