If there's no master keys at all, just a valet key, then you need to get a transmitter chip installed. The keys will come from the factory, as a Lexus dealer can get the key code. you might as well get a pair of keys, since the chip is more expensive than the keys (usually about $400-600 for the keys and chip).
The cracking of the wood's kind of intermittent on 1st-gen GS 300's; I see them on models with 30K miles, and then I won't see them on cars with 200k miles. Go figure. My 1st-gen has it on the shifter, but it wasn't anything Super Glue couldn't handle, since it was cracked, but not shattered. I wanted to use the aftermarket wood trim kits, but the raised surface wouldn't allow the ashtray to close properly on another model I saw.
Lexus dealers (usually) won't hand out prior service histories, unless you own the car.
Personally, I think $7500 is a little steep for a car that's over 10 years, 100,000 miles, and an iffy service history with an airbag light on...but that's me.
Moron.
Thanks for the information and opinions. It's been a lot of help. Carfax came back fine, everything normal. I'm having a pre-purchase inspection at the Lexus dealer tomorrow. Thanks again for all the help.