Hi racer256. No excuses needed for that skiing. For an old fart of 40, you're looking pretty good! (Note, I can say that, I'm 53 )
The first thing I'd suggest you work on is moving forward on your skis more. Watch the turn in which you go past the camera, you can see the constant aft position. If you move strongly into the front of the ski for the start of your turns you'll be able to produce a more aggressive turn start and thus be able to tighten your line. Right now you're just kind of hanging in the back seat waiting for the gate to come to you. Go get it!
You can see how this is affecting your line,,, it's rounder than it needs to be. You're also sometimes starting your turn too early, then having to hang there waiting to engage the arc. This is slow. Straighten out your line a bit, wait for the rise line, get into the front of the ski and engage like you mean it.
You also need to work on shedding the knee anglulation and introducing more hip. The knee stuff is a weak position, and limits the amount of edge angle you can use. It also makes you lazy with angulating at the hip. This lacking angulation at the hip can be seen in both the gates video and the tuck run. See in your tuck turns how you're loosing outside ski pressure too early at the end of the turn. It's caused by the body tipping into the turn too much, and as a result you're loosing the reverse camber release energy that could be used to rocket you out of the turn.
Hope some of that helps.