ok i know that it's illegal to bake at home, but what about decorating? I'm looking at renting space to bake in a commercial kitchen, but is it ok to do some of the decorating at home?

Per the Health Department (where I live) not even your tools can be kept in your home. You are supposed to do everything at the commercial kitchen.

Not everyone does this but it is what the Health Department wants.

Just call your local health dept. Better to be safe than sorry!