Oh. That explains.
Thanks for showing!!
The SL12 is made for carving turns. Either like in the video I linked to a post above, or larger GS like turns like in this video:
I think your technique is classic slalom turns. What you should really try is some straight earlier slalom racing skis. They were built to ski the type of turn you show.
Skis like theese:
They will bite into the snow immediately as soon as you give it some edge.
The current race breed won't bite in the same way. The ski's I'm showing you now will kick back like nothing else. I think you should be able to get hold of non carving race stock skis for next to nothing nowadays.