You will have to go on FULL VIEW to benefit from it. For example go to this link/free Guitartricks lesson: http://www.guitartricks.com/freelesson.php?input=YzE2ajhuazA0NQ==
The functions for controlling the video are:
Space to pause / unpause
A: Start the beginning of a loop
B: End the loop
1: Go Fullscreen
2: Normal screen
R: Repeat
UP/DOWN Arrows: Control Audio volume.
Hope that clears things up. You can use your mouse to jump anywhere in the video, but it would be useful indeed if that would be possible with extra buttons, but I don't know if that would be convenient since some videos aren't even 5 minutes long.
Anyway if you would like to some more lessons, who are accessible to anyway visite the Guitartricks Channel: http://www.guitartricks.com/channel.php
JJ