Just watching your video again it looks like the non-printing moves are happening at high speed. I would be inclined to think that you have something set wrong in Slic3r
Check the 1st layer speed setting. This can be either a speed or a % depending on how you enter it.
Try sending the following Gcode from Repetier Host and timing the moves.
Check the 1st layer speed setting. This can be either a speed or a % depending on how you enter it.
Try sending the following Gcode from Repetier Host and timing the moves.
G29;HOME G01 X0 Y-50 Z100 F12000 G01 Y50 F1200; Should take 5 seconds to move 100mm G01 Y-50 F6000; Should take 1 second to move 100mm