The problem with someone making a pre-made light show is that if you don't like their channel assignments, well, then you're screwed.
MyDMX won't let you move things around. It would be nice if it did, then it wouldn't be an issue.
Using the FX generator will be something you're going to have TONS of fun with. With that you can quickly do a lot of things. I like doing out of phase circles with my 2 movers. This is an easy thing to do with MyDMX. My problem with the FX generator for making movements with my moving head fixtures is that it takes me a bit to figure out where I want the circle restricted to, which again, is fairly easy to do with the FX generator.