ASo as you probably guessed I am NOT a fan of buttercream (no offense to anyone), I just find it offensively sweet. But it seems that all the good crusting recipes call for tons of powdered sugar like buttercream. Is there ANY way to make a good crusting recipe without all the sweet? I have been dabbling with ganache which I like but it doesn't really "go" with all cake favors. Anyone have some good recipes?

You can make SMBC, but you have to put it in the fridge to crust. 

Here is a tutorial, that is great https://www.youtube.com/watch?v=4XjNCncyziI&feature=my_liked_videos&list=LLV2jGJDr5epSmoAnIMhR9VQ and if you go t craftsy there is a free class on modern buttercream and he also gives a tutorial on how to make it and design with it. HTH.

Just to clarify, SMBC is great and lightly sweet but does NOT crust.  Putting it in the fridge will make it very firm and lovely to cover in fondant or whatever decorations and then it goes back to being its soft self once it warms up again (not soft like falling down, just soft like good to eat)

AI have had problem with icings seeping out before! I am in an EXTREMELY high humidity area and many icings I've used while searching for anything other than buttercream have melted straight out from under my fondant. Would this be ok to put under fondant? Does it hold up once at room temperature?

AOoooo, thank you! I love meringue :) I think I tried once before to make Swiss meringue buttercream but it never firmed up..maybe there was some oil or something on my beaters? I actually forgot all about it when It failed. I'll have to have another go at it...

Any meringue buttercream (IMBC, SMBC, or French) is completely different in taste, texture, and sweetness than a powdered sugar based recipe.  Smoothing is all in the hand movement and tool you use and really doesn't have much to do with crusting at all.  Meringue buttercreams don't crust.