Im making a wedding cake for my sisters boyfriends brothers wife (lol whew!) 

The Bride isn't expecting perfection but she has 160 guests and wants 160 cupcakes plus a small 1 tiered wedding cake (the catch is she wants a White Chocolate Raspberry Cake with Fondant Ombre Ruffles covering the cake) 

I need major help: 

First off how do I put the raspberry filling in the cake correctly? I know how to cut the cake and all, but do I crumb coat it first with buttercream? Or just cut the cake and put the raspberry filling in? Are there good raspberry fillings to use for a cake that will be sitting outside in the heat? (aka non refrigerated) 

Is buttercream best frosting to use under fondant? Recipes? 

How do I keep the cake from sweating in the heat? (The wedding is end of July outside midday) 

Last but not least, the ombre is light pink to grey.... whats the easiest and most successful way to Ombre a cake with fondant?

Whats the best way to bake the cake? (I mean do it 3-4 days in advance? how do I store it? Will it get dry? how do I keep it moist?) 

Any and all help is appreciated! 

Sorry for all the questions....I love baking and am no novice... but with the wedding cake I feel like one.