Thicker top bezel is the only viable one. But just at a glance it looks like the bezel + notch height is about the same height as the current bezels. I don't really see either option as necessarily being better given that.

Having it stick out is a no-go because things sticking out of a laptop are at risk of breaking off.

External webcam is something extra to carry around and mount. That's even worse than a dongle.

I don't agree that a notch in the corner would be less obtrusive. And the lack of symmetry wouldn't do the appearance of it any favors.

Cameras at the bottom have been done before and they suck. They're called nose cams for a reason.