Congrads on the 968!
Watch out for these killer on the 968's.
1. Vario Cam and Tensioning Pads are due for Change by around 70K-100K miles. Also Hydraulic Tensioner is due at 140K. Pads and Chain are under a 100. Hydraulics' is like $400. Failure to do so WILL result in death of your Head. (Bent Valves, damaged CAM Gears, and nicked pistons) Do not put this off! I think Clark has the pad checking procedure which is easy, but the chain swap means resetting your cams and timing. Can be Trick without tools but Clarks has some tricks for marking without tools.
2. 92-93s had weak Pinion Gears problems. But I hear those go by 26K or so. PO probably had fixed already.
3. Duel mass flywheel has some tendency to fail. Not as bad as the rubber puck in the 944's but still a potential problem to look at if you do a clutch job. Much much easier in the 968 with the 2 Torque tube couplers.
4. Change your Connecting Rod Bearings. If they go you can easily bend your Crank and spends lots of R&R time cleaning up everything. Ask me how I know.
http://forums.pelicanparts.com/porsche-924-944-968-technical-forum/286923-rod-bearings-968-ka-putt.html#post2639540
Clean the Idle Stabilizer and Throttle Position switch as previously noted. Also Check / replace Your Vacuum lines! The Vac line from Heater switch on front of heater rail over Exhaust manifold to same pressure regulator. I had a tinny one that ran from the Throttle Body under the intake arch and back to the fuel pressure regulator complete splinter.
Don't know of anything unique about mirror or window controls. They go bad or need contact cleaning / replacing. Doubt the motors a bad at that age. Wires probably OK.
Sounds like a great car to work on and enjoy. A little required preventive work and you'll have years of fun.
PM me if you can't find that Vario Cam inspection. I found a great 15 page word format with pictures.