Yup. Usually they take a lot of tweaking, and customizable starting points are the big seller in the professional world. Keep in mind, calling oneself a professional isn't just a question of quality; it also means a tendency to be constantly rushed. So time savers are pretty valuable.
Whoa... most of the projects I've seen have been custom made. Rare we'll use anything pre'made or a template. But the Video Co-pilot packages are A+ quality once your tweak them and create your own thing from them.
I've never used templates. I've used stock elements, and recycled old animations using new elements, but never presets. I do create my own templates and presets, but those generally have specific uses and are heavily modified by the end of the project.