No it doesn't show through. its a wee bit messy at the bottom, I have noticed but that be overcome using a fondant ribbon or fabric. but it does not show through - from my experience. I haven't done a cake for a wedding but have done tiered cakes. hth
http://www.youtube.com/watch?v=QgCu8-yrIxc try thisf site on utube. as for the ruffles never done it before. seems like straight long pieces which have been thinned out at the edge. i see a lot of this design cakes on CC. some one should be able to able to help you further.