Dunkelweizen is my favorite style. I brew it several times per year. I never primary more than two weeks, but I do secondary for a week or two depending on how patient I am. That being said, I don't think an extra week in primary is necessary. The secondary is also probably not needed but it makes me feel better. It sounds like you had a good healthy and vigorous fermentation so you could take FG readings to be sure and bottle at any point.