Please tell me how I can create a shortcut for grouping objects? If there is already one, I can't figure it out.
This article describes how to create custom shortcuts in Word 2013 http://www.groovypost.com/howto/customize-office-2013-keyboard-shortcuts/
EDIT: So I went looking for the group shortcut. If you go to "File >> Options >> Customize Ribbon" and click "Customize" next to "Keyboard Shortcuts", you will get a menu for all possible options you can assign keyboard shortcuts to. Under the category "All Commands", you will find the command "DrawGroup". (Note that when I assign a keyboard shortcut to this command, I can't get it to work, but I guess it might depend on what objects you are trying to group, so you could try to test it out or go through the list and see if I missed some other grouping command.)
I also went into PowerPoint to check which command Ctrl + G was assigned to, but as a rather weird limitation, it is not possible to customize the keyboard shortcuts in PowerPoint.