I have flown with cats a couple of times but it was a few years back and they travelled as cargo. They came through it pretty well, actually, but they were young.

I think the hard part about having a cat in the cabin with you is that you are supposed to leave them in the carrier and under the seat for the duration of the flight. If they get loose in the cabin, the FA's and other passengers may get quite annoyed (or more), so it's best to make sure they are always contained. You can't count on being able to bring the carrier up and on your lap or even in front of you on the floor. So I would think about how to show the cat you are there with them, and a certain type of carrier (that lets you reach in without the cat getting out) might make a bit of difference.

I wouldn't sedate a cat unless my vet recommended it and they didn't recommend it with my cats.

A familiar and favourite blanket or toy of course, but I'm sure you've already thought of that.

Your kitty may meow. I don't know what you can do about that. It's tough, because some people may find it annoying. I've flown when a cat was nearby and was meowing, but it took me awhile to even figure out what the noise was and I never really found it that bad. Is your cat a YOWLER?