My $.02First, in general, my experience is that it's safer to ski faster than the average speed on a crowded trail, within limits--more of the potential collision targets are in view ahead of you, your relative speed gives faster out of control skiers behind you slightly more time to avoid impact, the physics problems of avoiding collisions with the people you can see are easier to solve (you are going a different speed, and it's easier to slow down than it is to speed up.) A key part of that sentence, however, is "within limits"--depending on how crowded the trail is (and how many other obstacles) you have to dial back the speed a lot. In addition, I've skied with beginners who were seriously freaked out by what they saw as near misses from third parties (even if there was no actual danger of collision) so as an advanced skier you also have to understand that zipping by relative beginners without a LOT of room between you freaks them out (and should be avoided for that reason.)
In general, if you want to rip fast SG carved turns, do it at a time and place where there are no crowds. And don't do it right by the trees or lift towers, even on the flats. Expert skiers and racers die every year from some bobble/wrong foot/hooked edge/get back problem right at the edge of a flat trail next to the trees. (That's the fatal accident profile for skiers--easy relatively flat trail for the skier, run really fast, close to the tree--whoops plus WHAM equals afterlife pass.)
As far as speed control without skidding every turn:
First, as Rick points out, you can strap on slalom skis with their 12 meter turning radius, and the sheer number of turns will slow you quite a bit.
Second, start each one of those turns with an unweighted pivot entry, so that you're actually beginning your turn after a 30 degree change in direction (so the same turn puts you 30 degrees more across or uphill).
Third, even if you do pure carved turns, after four or five turns you can throw on the brakes either through a hockey stop or a turn uphill. (Or you can do what Bode Miller did a few years ago at the first WC GS race of the season in Austria, and power slide every other turn.)