I watched it once. I was pretty okay with it.
1) They're going for a specific style. Of course some shows look more polished using the same animation tools, but they aren't all meant to look the same. The animation itself looks fine in my opinion, and I've noticed no lip syncing issues.
2) I agree, but then I figure a lot of the things I found funny as a kid probably aren't that funny now, our senses of humor have developed, we remember things as funny, but if we watch them now, they probably aren't what we remember.
3) I'm fine with the characters. I don't think you want to like them, so everything they do annoys you, I'm not saying I've never done this, but they're not as bad as you describe.
4) Many kids shows have creepy themes, watch "Courage the Cowardly Dog." Yes some of the plots are shallow, but what do you expect? You're asking for a rich narrative from a kids show. I think stereotypes are funny, and many shows use pain as a source of laughter.
I'm fine with your opinion, but I don't really see what's so bad about the show. I'm not going to over-analyze a show meant for kids ages "2-11" especially considering I'm 16, and didn't mind it at all. =)