I am in difficult situation because I'm trying to meet the taste palate of my guests who are mostly traditional and Vietnamese. In fact, their only experience of a cake so far is French cakes, which is different from our American cakes. And right now I'm focused on finding the right baker for the wedding cake.

What I'm looking for is icing that tastes like a European torte; like it's still rigid so suitable for decoration, but it tastes buttery and not as creamy. It's actually bland compared to the icing on most grocery store sheet cakes.

It appears like most bakers have a set recipe for their icing, which is butter, shortening, and sugar. I'm very cool with that, that's no problem. But I just wonder if they're able to just modify what they already use, as in decrease the sugar and increase the butter? Would the only change be that it would require refrigeration since it would be made of mostly butter now? I know nothing about cake recipes so I don't want to insult them.

I really hate the situation I'm in because I feel like Bridezilla. But I know that the guests will only accept a slice and eat a couple bites of it to respect me. But they won't like it or finish it.

Any help would be appreciated!

It depends on what kind of frosting you are talking about.  Buttercream is exactly that- butter (or shortening, depending on the bakery) creamed with sugar and usually some milk as well.  Can't really alter it without significantly changing the texture.  And fondant is obviously sugar paste- however, fondant was originally adhered to a cake with an apricot filling of some kind, which could be less sweet than buttercream.  (The whole gluing fondant on with buttercream happened when buttercream-loving northern european and american brides fell in love with the smooth lines of fondant, which was originally used in a warmer climate where butter-based frostings were a bad idea.)

There are many other frosting recipes aside from buttercream and fondant (if you want to count fondant as a frosting).  What's coming to mind for me is royal icing (like the kind you glue gingerbread houses together with, which may not really be royal icing and just what my family CALLS royal icing) and using whipped cream as icing.  I would express your concerns to your baker/baker candidates and see what they have.  A good bakery SHOULD be able to make more than one kind of frosting.

Also, not every piece of cake is going to have much frosting on it, only the ones from the outer rim.

Try a French meringue buttercream or an Italian meringue buttercream.  They're much less sweet than traditional American buttercreams.  You can find tons of recipes online, and I've even found tutorial videos on YouTube.

This is old, but in case this helps people in the future: Chinese bakeries have awesome cakes and their icing is traditionally creamy and not too sweet. I love cake (and cream) but too much sugar prevents me from eating as much as I want. ;)