I'm curious as to how exactly the Sentinel big fig is affected by the Crosswinds BFC.

Does the 2nd sentence of the bolded text occur because of the "standard flying rules", or is it a special ability unique to the Sentinel, because it's the Sentinel?

If someone plays Crosswinds, does the Sentinel still get to ignore hindering and elevated terrain?

We had this come up recently, and because it specifically says that Sents ignore hindering and elevated the BFC didn't really affect them too much.

That sentence allows them to ignore the effects of hindering terrain and elevated terrain on movement even when Crosswinds is in play. What this would mean, though, is that they cannot carry a character when Crosswinds is in play...but they can still capture. And they would need to stop if they moved adjacent to an opposing character.

Gotcha. Like I said, that's the way it was played, just wanted to make sure for the future.