There's a reason jumper cables are as thick as they are - coincidentally about as thick as the power cable to the starter motor. Try powering your starter through anything less and you'll be left with an ugly puddle of melted plastic - at best.
And yes, the kill switch (like the kick stand switch) is intended as an emergency feature only (eg: if the bike's laying both on the key and your leg). That's why they're always red. I keep telling a friend of mine that and he insists on ignoring the advice, and flattens his battery roughly once a month. Use the key to kill the bike and you'll never have that problem.
