Much of this movement is to regulate the contents of the cell. This includes bringing material into the cell from the extracellular environment or the plasma membrane (endocytosis) or releasing material made within the the cell to the outside (exocytosis).
It really is an easy project...it just takes a little time. All and all, it took me about 6-8 total hours to make 4 bouquets, 10 bouts (my mom made those though) and about 15 centerpieces. I made two bouquets the day before our wedding and the other two the day of the wedding.
My recommendation would be to give your self 2-3 weeks BEFORE your final count is due at your venue. So if you have to have your final count in 2 weeks prior to your wedding that would be 05/8/11. Three weeks prior to that is the 04/17/11. Your FHs estimate of 04/15 is about what I would do.