1) Check the for sale forums. Lots of cars being parted out and I'm sure you can find one for a good price.
2) Starter bendix is sticking. Common issue. Fix by cleaning and lubing the bendix.
3) Likely a bad door latch switch is making the light turn on and off. The cluster lights are supposed to stay on for a few minutes or until you lock the car. The switch on the dash is for locking from the inside.
4) Check the owners manual for bulb types:
http://p914-6info.net/Boxster_Manuals/986%20owners%20manual.pdf
5) Again, in the owners manual. The one light is the rear fog light and there's only supposed to be one. The other side is a dummy bulb and not powered.