No Key!?!? What do i do?

Should be a key code stamped on the ignition cylinder. Side or bottom. Ought to be a letter followed by five numbers.
I believe Yamaha dealers may be able to cut new ones with the code, some locksmiths maybe too, but I ordered mine from http://www.keys4urride.com/

How about some pictures or a build thread?

 

I had my key redone in Australia at a locksmith at Sumner Park Qld for around $35..... as long as I knew the number that was written in the cylinder where the key goes. I had one company want to charge me $250 to do it including a call out charge so it pays to ring around.

 

Or order a new switch with keys off of fleabay...

 

Won't get him into the gas tank.

 

I'd just put a switch in behind the light.
an SPDT should do it.

 

Oops! that sort of kills that one. I've always found with older vehicles of same make that another key works with some jiggling.
I had 4 Ford Cortinas' that would all unlock and start with the same key.

 

Ya...forgot about the tank for a minute, a mechanic I know told me that he opened the tanks off of older bikes with a flat blade screwdriver sometimes...but you'd have to change the gas cap afterwards....