1.) As Jake said...
2.) Depends if you need that window later on again? If yes, just hide it with HideGadget( Logic_Gui ) and show it again with ShowGadget( Logic_Gui ). If no, you can free it as Jake mentioned to get rid of it, but that needs complete recreation if you want it back.
Off topic: You probably want a different name for your program, to do so just open the Properties Editor and click on the left side on 'Main Window' and edit the text now visible in the tabber.
2.) Depends if you need that window later on again? If yes, just hide it with HideGadget( Logic_Gui ) and show it again with ShowGadget( Logic_Gui ). If no, you can free it as Jake mentioned to get rid of it, but that needs complete recreation if you want it back.
Off topic: You probably want a different name for your program, to do so just open the Properties Editor and click on the left side on 'Main Window' and edit the text now visible in the tabber.