Ya not bad......but here are some Golden Rules for you. There is easily a tenth to be made up here.
Rule #1: Minimise snow resistance.
Rule #2: Minimise distance travelled.
Rule #3: Minimise air resistance.
Follow them in that order....the practical application of this for you is, dont be afraid to get out of that tuck! It totally killed you on that first big turn that you see...ie where you skid and you get wide.
If you had broken your tuck, it would have aided in your ability to get long and to extend more into the fall-line. This would have given you more pressure on your skis earlier, and greater edge angles...thus snow resistance would be less (ie less skid), distance was shorter (tighter line)....you didnt minimise air resistance...but that is irrellevant...as you need to follow the golden rules in order....
The order is crucial....always leave your tuck if it will improve your ski performance.....always choose your line to be smooth...ie minimise snow resistance....only tuck when you can still meet the above 2 rules...in this case that is most of the run for sure....but not ALL of the run.