To bad your not in the USA, as clutch baskets are a dime a dozen used on ebay. I've had difficulty using the kick starter when cold, but wanted it anyway as an emergency back up. Head light cutoff is easy and a worthy mod in conserving power. I would be leary of using too much electric gadgets on the DRZ, it's only 200 watts at best. If your running extra electrics you really need a way to monitor the voltage. Here's a handy little idiot light.
Here's an all things DRZ for a long list of mods.
This maybe too late for you, but watch the DRZ counter shaft for leaks. It is well documented on Thumper Talk, do a search, if it starts leaking it could be a warning that the tranny is going bad. I heartily recommend taking a counter shaft seal, spacer and O-ring, it's a 30 mm socket to remove the CS nut. PLus you better have a steel rear sprocket and not alloy.