If you have console enabled (and you have), then at first put >devcommands< in it and then put >debugmode< command (both without brackets). When debugmode is active, you can use >z< button in game - not in console (on the left up corner of screen you see "debug fly: true" or "debug fly:flase" after each hit of z button) and >b< button in game - not in console ("no placement cost:true" or "no placement cost:flase" on the left up corner) and workbench is not needed in this case. If you have flying mode active, with >space< button you fly up, with >ctrl< button you fly down. You can use e.g. >spawn< command for items. Then you also can put >god< command or >ghost< command (or both - also without brackets)... It must work ...