FCC, ROHS and CE certification and compliance
I can answer part of this.

RoHS is self-declared; get the RoHS compliance statements from all your component manufacturers, keep them on file in case someone challenges you, and you can declare your product to be RoHS compliant.

CE is self-declared, but typically much more complex. Even identifying which standards you have to apply to your product takes some doing. (Simplest route is sometimes to just look at what standards a comparable product declared under.) I would strongly suggest hiring a third-party evaluation lab. I think UL does that sort of thing now, I've worked with F-Squared, and I'm sure there are many others.

I've never done FCC.