>>Should I request that the timing belt be changed before purchase? <<
The normal timing belt service occurs at 70,000 miles, so youve got time

>>Does the CEL it come on at preset intervals as a reminder for routine service or is there really something wrong that needs to be serviced? <<

Uh oh....No, what comes on as a service reminder is a little red light. The CEL is generally significant, the cause of which should definitely be determined before you buy it.

>>Should I ask for a set of new tires? (Handling can't be very good with those "Wintermasters") <<

The stock size for tires on the Turbo was 205/50-16 before 1996, when they went to 55 series tires. If you can get them to give you new tires, obviously that would be better...Either size would be good, but after having used both, I prefer the lower profile size.

>>Can I turn the light off at home without going to the local Volvo dealer? I have always done the work on my cars but have never owned a (new) Volvo.<<

As indicated the cause of the CEL must be determined and corrected before you buy it...The srvc light prior to '96 could be turned off by DIYers by manipulating the under hood Data Link Connector, which was also used to read fault information..Unfortunately after '95, Volvo did away with this option, so that to turn off the srvc light now, you have 2 options: go to the dealer, or buy IPD's tool for $299.

I've found my '95 850 Turbo to be the most enjoyable car I've owned. I've added the IPD ECU, Sport Exhaust system, and Sport tuned sway bars. Its a fun car to drive as stock, and even more fun to upgrade...Mine has been extremely reliable, and I would highly recommend it. good luck with that light, though!!!