Frustrating to use non-standard hotkeys

Here are some of the non-standard hotkeys that apparently I'm going to have to learn (Windows user):

Closing a tab: not Ctrl-W, but Ctrl-F4.  Not exactly non-standard, but Ctrl-W is so much more convenient.
Moving between tabs: not Ctrl-PageUp/Down, but Alt-Left/Right.  What?  Who else uses that?
Renaming a file: not F2 or Ctrl-R, but...Shift-F6?  And copy is Shift-F5?  Why??

Second day using RubyMine, so I'm learning I guess...