yeah, Captaining a tandem (which is heavy) takes a lot of upper body strength. I would say it's made my Dh a better rider and a STRONGER rider too.
having said that; are you telling me that you don't have this bike yet and will be trying it out for the first time when you are on vacation? I hope you will be near a bike shop who can fit you, etc...

stopping, starting, dismounting.
let's start with getting on the bike. He gets on, holds it steady and then you get on when he's ready.
Starting. You're already all "locked" in so you give him a pedal, have the one up that he likes
and then you gently push him through while he gets himself clicked in or whatever to the pedals.
stopping. HE TELLS YOU that he's slowing down or stopping.
other wise, YOU get your legs hurt. after you are stopped, like at a light; you just sit there unless
you have to get off.
Dismounting. he gets into a braced position and tells you when he's ready, and you get off.

As big as your dh is, he should be fine and a good enough rider to pilot the thing. He just needs to learn to do what you tell him..