I'd absolutely buy another one again, and I have even had a few emissions related issues. I'd still buy another one. The emissions system is really the only problematic thing about these cars, and if I have a failure out of warranty, it can be deleted. That is my plan if it happens to me. The driveline in the diesel cruzes has been pretty much rock solid.
Parts are not hard to get and won't be hard to get for a very long time. If you want a part, walk into a dealer, tell them the part you want, and they will order it for you. Or hit up rockauto.
The spare tire thing is not really specific to the Cruze or to gm. A lot of newer cars have been doing away with spares to save weight and make room for other stuff, in our case the def tank. With the combination of people who have something like AAA or a roadside assistance plan, the amount of people who get stranded by a flat tire these days is relatively small. That is why spare tires are beginning to go away.