Hi! First, great questions and thanks for posting them! However, in the future, please limit each forum post to one distinct topic, so people can more easily follow the thread, and search and find the topic later. You've got at least a couple of different questions posted here.
But, regarding your questions, I'll take them in order:
(1) The flowers on the cookies in the background and banner were handpiped with royal icing by member emilybaking. No molds were involved.
(2) There are a kajillion online sources for cookie cutters. I really like the plaque (and other) selection and service at Cookie Cutter Kingdom. I also use a lot of standard Ateco nested cookie cutter sets (basic rounds, ovals, etc.) For molds, I usually purchase from First Impressions Molds, but sometimes elsewhere depending on the type of mold I am looking for.
(3) I really can't answer your third question, as it is too vague. There are so many cookies with bouquets on this site, made in many different ways. To get a helpful, meaningful answer, it would be best to provide a link to the cookies you want to better understand. Or to contact the member who created them (if you found them on this site) to inquire. The creator's contact information can be found by clicking on the name in the upper left of any image posted to this site.
Hope this helps! Again, one question at a time in the future would really help us to keep these forums organized. Thanks!