Random Fitness Questions

Surely if there's one thing you can easily see when watching the Olympics it's that fit bodies come in a lot of different shapes.

Why would an elite athlete's stomach set your teeth on edge?

Hey, remember a good few years back when somebody wanted someone with muscle for a private posing session? Like, not to teach how to pose but just wanted someone to come and pose in front of them. Well, I thought that was the weirdest thing I was ever going to read in this forum... Until now

That's the one

I've got a squat question if you don't mind. I recently started doing squats again after a long injury-forced hiatus and I've noticed 2 things;

1 - my hips sway slightly towards my right leg on both the eccentric and concentric phase (recentering at the bottom). It's a subtle shift, probably no more than an inch, but as I'm looking in the mirror I can see it happen. I'm not using much weight and am completing 4 * 8 so it's not that I'm overloading myself. I have to really focus on keeping myself aligned for it not to happen but I'm wondering whether it's something I should be bothered about at all or whether it's pointing to a weakness or tightness somewhere?

2 - when I reach the bottom of the movement and start back up, I feel like I'm pushing through my trunk/core and I don't feel like I isolate or focus on one particular muscle group, however, on a few occasions it felt like I was pushing more through my quads, or at least it was tougher on my quads. I was also able to replicate this and push through my quads more. My question is where should I feel like I'm pushing from on once I start back up?

Thank you and funnily enough I've been watching a lot of RP lately, Dr. Mike is hilarious and informative! He's just released a squatting for size video that's on my playlist.

Thanks for the general advice too, I'll take it handy, I really don't wanna go back to being injured again.