I went to Alinea with two vegans, two aging punk rockers who haven't worn jackets since they're respective wedding dates, and a woman headed to the ER after dinner because her doctor believed she might have a kidney stone. We had animated conversation and lots of laughs, and I'm guessing we committed an etiquette gaffe or two during the night.
The Alinea staff took all in good humor and treated us like we mattered. Even better, they don't take themselves overly seriously (our sommelier relayed in rather colorful detail the story of passing his own kidney stone -- and this was over our first course!). Maybe it's because the food is playful, or maybe because the chef and his staff know they're turning out exceptional food for appreciative guests, but I found the service to be the warmest and most forgiving I've ever experienced.
Honestly, I think you'll do fine. There's no such thing as messing up, because who really comes in *knowing* how to deal with the lavendar pillow? Or the dehydrated bacon with no utensil? This makes the whole Alinea experience an equalizer of sorts.
Go, enjoy, mess up a little, and laugh about it then and later. I'd say the only expectations are showing respect for the food and the staff, which I promise will be reciprocated.