Yes it is.
no
A 3.4 liter GM engine is an interference type motor which has very tight tolerances. If the timing is off slightly, it can result in catastrophic failure.
Yes it does. (check the GM section of this list) http://www.aa1car.com/library/timing_belts_interference_engines.htm
As you listed this in the Saturn Vue category I will assume you have a Saturn Vue. The 2004 and up Saturn Vue engine was manufactured by Honda and it is an interference engine. The belt and water pump must be replaced every 100,000 miles. All other years used a GM V6 that was also an interference engine. The 4 cylinder Saturn Vue did not use a belt but had a chain.
The GM Saturn Sky was released in the year 2006 as a 2007 model.
It is/was part of GM
The Saturn was an experimental project for GM. Some of the lessons learned were used on other vehicles in the GM fleet, but in general, the Saturn was a unique vehicle.
Yes, it does.
Yeees?
GM
The bigger valve is the intake.
The General Motors 3100 family of after 1996 underwent a changeover to interference designs. This standardized GM powertrains design across multiple platforms such as the 3400 and 3500.