Ok, I'm doing an egg free/ nut free cake from scratch... (just so I know there are no eggs in there) Icing with buttercream.. and covering with Satin Ice fondant ( checked with them and it is egg free) Why am I sooo paranoid that I'm going to kill a kid??? Has anyone else been nervous about special cakes like this or am I just mental in the head....??
I don't think you are mental--it's a big deal. Have you thought about having the customer sign a waiver (since you are not, technically, a 100% nut-free facility, you cannot guarantee without a doubt that there is no risk--no matter how small--of cross-contamination). Although my guess is, as the parents of the allergic child, if they are willing to get the cake from you, knowing you are not a nut-free facility, then they probably are not too concerned. I, personally, do not make such cakes, because I can't guarantee they'll be free from cross-contamination.
Just be very careful, wash down all of your counters, workspaces and tools that will come into contact with this cake (lest there be any residual nut traces from past projects) and wash your hands OFTEN (you never know if you move a jar or can in the pantry while looking for something for the cake and that jar has trace amounts on it). Some people might say this is going too far, but for some allergic children, a tiny speck is all it takes to trigger a reaction, so be mindful.
I think it is normal to be nervous. Although it does get easier the more allergy friendly cakes you make. I would say 80-90% of the cakes I make are allergy friendly. The only allergy I haven't attempted to accommodate is gluten.
PinkZiab had good advice about cleaning before and often. Of course keep any products containing peanuts put away for the duration of your baking and decorating.