Can I get my tubes tied at the same time as a tummy tuck?

Yes. However, while tubal ligation may be covered by insurance, a tummy tuck typically is not.
Yes. Just ask your gynecologist to coordinate with your plastic surgeon- shouldn't be a problem.
Yes, but... Assuming that this is an elective tubal ligation, it would be fine to get a tummy tuck at the same time. If you were to get a tubal ligation in the immediate postpartum period, i think most plastic surgeons would hold off on doing the tummy tuck. The skin would need to get back to an "unstretched" state before an accurate tummy tuck could be done.
Yes. Yes, they can be combined and the incisions can be made after the tummy tuck skin incision is made so that no additional scars are incurred.
Yes. Great idea, but must be ok with OB gyn who is to do that part. If the plastic surgeon consults the OB gyn it's usually "yes".