Not sure on the shortcuts ... but the hidden window .....
To open / hide windows its a control + (letter for window ) on the PC side .... guessing since control is now right click on the Mac version, Its probably going to be Apple+letter
For example - to show / hide the casting bar its control + S
Guessing main bar is M ??
Sorry couldnt be more precise. ( Actually let me launch and check ... BRB )
*Update 10 minutes later*
Option + W Will bring back your "Window Selection"
Khama Khameillion lvl 52 Illusionist / 250 Grandmaster Jeweler of Sullon Zek
Khaamma lvl 60 Phantasmist / 181 Jeweler of Al'Kabor