The tires will wear out faster if you DON'T get the alignment. If you get the alignment, tire wear will be the same. It's hard to say what will happen to the shock/strut service life, it will depend on the spring rates of the lowering springs. Basically, if the spring rate is higher, then the shock will be working harder, so it will wear out sooner. If they are similar, it won't be as big an issue.