So I've installed ControlX (wew that was a spooky process), and I'd like to delete BtMg because I don't want to accidentally screw anything up with it. I don't fully understand the purpose of BtMg or how it works though, so I don't know if I need to keep it around. Thanks.
No, you don't need to keep it around.
It may become useful later though and as it doesn't consume much space, why not just leave it?