I hit all the DTD locations to trade Vinylmations tonight.
By the way, one CM told me the Star Wars set will not be released until May/June, to coincide with Star Wars Weekends.
I asked at three locations their procedure for the blind box trade. The first one told me if I selected a number from the blind box, I would have to trade whether I liked my blind choice or not. I passed on this one. The second one told me I could elect to not trade after I saw my blind choice. This CM also let me take a second choice. I liked neither, so again I did not trade. The third location also told me I didn't have to trade blind, saying they were "cool here". As they opened the blind box, I mentioned I was hoping for any from the Muppets series. The CM volunteered up Rowlf from the box, at which point I told them "sold" and also that they were "very cool here".

The point here is that every CM is different, so ask!
You will also see "open box" clear cases with three figures inside, always by a register. If you like any of these, you can trade for it on the spot. I did this tonight too.