Honestly, you might benefit from watching skiing at the Olympics. Watch the gold medal runs for super G and moguls. Look at their legs, upper body, pole placement, and where they are looking. Listen to the commentators as well, they are usually pro or former pro skiers themselves. Ski at the speed you want to ski, if you’re going too fast just turn more and use more of your ski length. Pizza means nothing, turn your whole ski perpendicular to the end of the trail. Watch hockey players to figure out this leg movement.

One of the reasons I love this sport is because there aren’t “correct” answers to your questions, other than “it depends”. In order to regulate your speed down a run, you turn. That’s it. That’s the whole sport. Everything else is simply responding to the conditions around you. Multiple feet of powder? You’re dealing with some soft bumps you could probably rip right through. Visible ice and rocks? Your ski is not going through that bump, you’ll be in the air if you hit it with speed. So, it’s up to you and the day you have.

I can’t be specific because it’s really just up to you and what you’re comfortable with, but I’d definitely lean on instructors to master harder trails at wherever you’re going, and maybe bring these concerns up to them.

TL:DR; Just send it