You don't need to uninstall VSL to use ME - in fact it is useful to have installed, as you need it to add new videos into your Scratch Live library. I'm sorry, but I don't really understand what you mean when you describe the first issue. My best guess (not really understanding what you mean) would be that you might have assigned the MIDI crossfader to the buttons that show/hide some of the windows. If possible, could you to create a video of it and upload it as a private video to vimeo/youtube?