Shortcut Questions

I'm using PhpStorm EAP 96-1061 on Mac.

I tried to "block comment" some code. In the menu I see ^? (I don't know how to do that on a german keyboard), I found an overview card which tells me cmd+alt+/ (I don't know how to do that)
http://www.jetbrains.com/phpstorm/documentation/PhpStorm_ReferenceCard_Mac.pdf

Also on the right bottom there is a hint to open the "action search": Ctrl+Shift+A which does not work, but Cmd+Shift+A works. If I click on the search result the code is not commented, only if I select it with keyboard arrows it works.

Working with these shortcuts is annoying. Perhaps someone can tell me how what I should press on my keyboard to get this shortcut working.