The shot gun thing is a cartridge starter, I'd have thought just about all the flying chippies have been converted to electric start as its much easier.
A friend of mine is looking into the possibility of converting his gypsy engine to electric although its not for a chippy (it is for a classic british aircraft though).
James,
You're right - I can't recall the last time I saw a cartridge-starter-equipped civil Chipmunk; I've certainly not flown one. It's quite expensive to buy the cartridges and nowadays there are practical & legal difficulties about storing and using them (firearms regulations

). Removing it was one of the changes usually made on civilianised T Mk10s.
Regarding electric starters: there are several types that can be fitted and your friend would be well advised to research availability of spares. The problem is that with a small number of aircraft and several types of starter, plus decades of use, starter parts are sometimes hard to come by. It's often the clutch that's the problem area, and it is not unusual to hand-swing the prop to save on starter/clutch life: try doing THAT in FS

.
Hinch,
brakes to avoid crossover
That I don't understand. The brake lever is on the left side of the cockpit, so to use it you move your left hand from the throttle to the brake: there's no swapping hands and it's quite easy to use, even for someone brought up on toe-brakes.
What can be a bit tricky for an inexperienced pilot on the Chipmunk, is the use of carb heat and flap on a short field touch-and-go. The pilot has to move his left hand from the throttle across to the rhs of the cockpit, just under the sill, to close the carb heat, then put his left hand on the stick and simultaneously his right hand on the flap lever, all without taking his eyes off the runway ahead

. Then he has to swap them back in order to open the throttle.
Cheers,
Kevin