Rotation with indicated degree Rotation with indicated degree

Basically I have two questions.
 Is it possible to manually specify the rotation step (For example: step = 5 °)
The option in which this value I need to set from the keyboard: Rotation + Y + 5 (45) is not considered.
May be for this purpose is there a special tab?
After reassigning hotkey combination "Ctrl + Rotate / Scale, etc." stopped working.

Now the "Ctrl" key works with the operation of "Edge Loop Select", and "Shift" with the "Pick Shortest Path"

Is there possible at such a hotkey combination to resume operation "Ctrl + Rotate"?
You may try to reassign the CTRL+R hotkey combination to other hotkey combination
Go to Blender user preferences > Input > search for rotation > and reassign to whatever key combination you want