I'm with emwithme - I am so glad that in the UK we don't do cake smashing. And I've never seen the chicken dance at a wedding either, nor have I ever seen any sort of money dance, and I'm not sorry.
From a different direction - I've made celebration cakes for people. Never a wedding cake, but I know several people for whom their wedding gift from a friend was the cake. In a lot of cases in the UK, the cake itself is made by some member of one of the families and then professionally iced. Now British wedding cake does still tend to be heavy fruit cake and not really up for smashing, unless cake smashing is a euphemism for assault and battery but... if I had dropped a lot of money on making a wedding cake for people I loved, and the best they could think of to do with it was grind it into each other's faces and hair, I would be furious. I wouldn't say anything - after all, as we all know, once a gift is given it's the property of the recipients who may do what they want with it - but I would be mortally offended that they could think of nothing less disrespectful to do with my gift.