Not watched the whole vid but:-
1) Drop your saddles. Gives you more space to move around on the bike.
2) You're looking into the corners not round them. It starts off OK, but you never seem to actually look at the exit. You get through 90° then get transfixed by the edge. LOOK where you want to go. As your head turns, your shoulders turn, and the bars follow.
3) Don't hang so far back off the bike - you've got absolutely no weight on the front wheel, so funny old world - it'll skitter over the rocks in a straight line, rather than biting and turning. Unless it's truly, truly bastard steep (hands lower than feet kinda thing), you can stay far more centered on the bike than you would think.
4) Carry just a little bit more speed - you need to have enough momentum to roll over your chosen line.
5) BELIEVE YOU CAN DO IT!
Stevo - Looks like Lavarda...?
edit - watched the whole thing now - you're better on the smoother less steep ones, but still lack confidence and are snatchy with the brakes. Overall, you're riding very XC biased setups. Big tyres, big bars, big forks, short stems and slack angles make that kind of stuff a lot easier (although it does make getting up the hill harder, sadly). Bike setup won't magically give you the ability to ride tight stuff, but it does give you a bit more confidence/control. Personally I'm an advocate of a bit of armour as well for that kind of riding, but each to their own.
Keep practising - it'll come. I'm not sure how long you've been riding for, but that's pretty serious terrain and there's an awful lot of people who frequent this forum who would struggle worse than you do.