I had no problems at all flying with my vape stuff last month to and from Vegas. Just carried empty tanks and my batteries in a case in my carry-on, put the juice in my clear plastic baggie with other liquids, and nobody batted an eye. One of my juice bottles did leak a little inside the baggie once we were in the air, but that wasn't so bad, and might have been from me not screwing the cap on tight as much from changes in air pressure. I eased my one nicotine fit by dipping my pinkie in some of that spilled juice and rubbing it on my gum, which was nasty and maybe not safe, but kept me from freaking out as I am not a good flyer AT ALL.
I wouldn't vape on a plane. I know people talk about doing it, and some people have got away with it…but if you get caught, the hassle would so not be worth it IMO, possibly at the very least diverting your flight and you being kicked off, maybe even fines/criminal charges, plus being that PITA who caused everyone to miss their connector flight, plus giving idiots ammunition against vaping...