1998 Camry.... a few questions

Your belt is on borrowed time - you should change them every 140k km.

Yes

I've never heard of a passenger-side deactivation switch in a Camry of this vintage, although my Ford F250 of the prior model year had one. In any case, the best place for children is in the middle of the back seat, but you probably know that.

It's possible but you need to install a warning placard and ability to reactivate. Long time since I've read procedure. Check Google for "air bag deactivation"

Toyota recommends 6 years or 90K miles. That should work, but the older 5 years or 60K miles schedule seems much better.

I like to replace the following components while the area is apart (USD $,

======= FWIW, Toyota also recommends Toyota parts.

Thanks for your replies everyone. I went through the service bills the previous owner had given me and the timing belt was replaced by a Toyota dealer at 88,000 miles so it looks like I'm good for awhile yet. I was unsure about the interval for changing them as my last vehicle, a Previa, needed the belt changed every 60,000 miles.

It is a non-interference engine, so the worst thing that would happen is that you loose engine power, but no damage to the engine will occur. The percentage of botched timing belt change jobs is amazing high (even when done by the dealer), so take that into consideration also.