I know from experience that it is not good for machines to be stored for too long without being run occasionally. I guess that goes for any electrical appliance! My over locker and sewing machine were put into storage for five years when I went to live overseas, both needed servicing after that and neither of them went as well ever again!
I also think machine embroidery is not for everyone, you either like it or not, I personally think an embroidery machine is a lot of money for what you get, I would much prefer a machine which I could sew regular things on but which I could quilt my quilts on as well, these do fancy stitches too, so I got maximum use all round with it. it also depends a great deal on what you want to sew and how much sewing you actually do in a week or month etc.
Gal