I think by using a scrapper to smooth the sides of a cake, you can get a smooth or ridged scrapper at Wilton. All u need to do is place the scrapper at an angle of ur cake side and roll the cake on a turn table to get ur even sides.
And if its realy hard to get smooth sides then we could jus use a wid tooth comb and repeat the same process above.
buttercream cracking: if buttercream is over beaten or underbeaten it cud cause the buttercream to crack and curdle the butter.
we should also include buttercream cheats, whereby we could use hardened whipping cream or white chocolate to get a faux buttercream consistency which is lower in calories and fat.