Re: aircraft pod
I'm not sure it would actually be quicker.
You need to refuel the aircraft, the pilots need to do pre-flight checks, much of that can be concurrent with the passengers getting on so a lot of that 15 minutes isn't really wasted. Swapping the passenger pods won't be an instantaneous event anyway and could even be slower if you're waiting for one of the limited number of pod handling trucks to come to your aircraft. Then you need someone to check that the pod is most definitely locked on to the aircraft and that there isn't an iced up bit of the mechanism somewhere, that takes time and potentially could go quite horribly wrong.
On top of it all, you've added extra weight and complexity to the aircraft which worsens your fuel economy and increases the amount of time your aircraft spends in servicing. It's just not a good idea.