Oh no, I'm terrified of clowns! Seriously, this is a big no-no for me.

No offense, but this made me giggle! My husband has a 40 year old male cousin who is also still terrified of clowns. I don't think you are the only one out there! It seems to be a pretty common phobia.
Don't worry, unless you absolutely adore Dumbo regardless of the fact it no longer has the same feel or view as it did in the Fantasyland center, you aren't missing much. We were there last week and we are NOT at all fans of the StoryBook circus area. I understand why WDW did it. They had to find a way to save Dumbo as they had to move it for the AMAZING new Fantasyland, and it no longer fits with the Fantasyland theming at all. Really if you want to save and move the classic Dumbo ride, what other theming could they really do but Circus? So, I completely get it and appreciate that they saved Dumbo. I'm sure they knew it would be an uproar if Dumbo got the boot.
However, the Dumbo "waiting" play area is an absolute disaster. First the ride is pretty much walk on since there are two of them now and it has lost the "middle of Fantasyland luster" that pulled in so many riders (hopefully once the 7 dwarves coaster is finished and the wall comes down, there will be some better views and it might get some of that back). Second, when Dumbo is walk on, you can hear kids yelling at their parents that they want to play in the play area, not just ride the ride, and parents who are trying to just get their kids onto the ride and move on to other things. The CMs will give the parents a beeper and let the kids play even though the ride it walk on, but most parents (including us) weren't thrilled to lose their kids into a play area, that aside from a couple of cute theming things (Dumbo hanging down and some special "fireworks"), is pretty much the same type of play area you can find in some of the fast food restaurant chains or malls. Third, the play area is kind of dark and it is hard to spot your kid when they climb up in the tunnels, so we saw lots of panicked parents trying to locate their little ones, and there was a CM who was going up and finding and retrieving kids. Lucky her. They give you a beeper for the play area if you choose to go in there even when the ride is walk on and they wait probably 8 minutes or so to beep it so that the kids have time to play a little. Then, good luck dragging your kid out of the play area to ride the ride. We saw lots of parents trying to find and drag out complaining kids and screaming little ones. CMs kept coming on the loudspeaker telling people when their beeper went off they needed to exit and get on the ride, to try and convince the kids to come out when their parents were yelling at them. It was a madhouse of frustrated parents, including us. All the parents back there, including us, were talking to each other and commiserating on how much we absolutely hated that spot!
The characters back there are really cute (Minnie, Daisy, Donald, Goofy), but you will also probably find some crying kids in that area too. They made Donald a "snake charmer" with giant snakes on either side of him. We observed more than one of the really little ones who didn't want to have anything to do with Donald because they didn't want to get near the snakes. They got upset because they wanted to see him but didn't want to get near the area. We saw a couple cry. DD is 6, and well aware the snakes are fake, but even she did not want the snakes in the picture, and made me promise to crop them out before she would get near Donald. Personally, the snakes and theming are really cute, just not the best idea for a character in a section of the park primarily designed for the 5 and under crowd (Dumbo play area; Barnstormer; water play area and 4 of the Mickey Mouse Clubhouse characters. ). It is great to have the Barnstormer back up and running again though.