Frankly, I think it might be interesting to have a race that doesn't need food or drink. I have an idea for when I finally get the time to learn lua properly and do dfhack scripts of my own, but I don't mind sharing it: make it instead that they need to sacrifice one of their own number, and it must be one of their own, to (in the goblin context) appease their masters.
The fact that they'll only be drinking alcohol rarely means that, unlike what we have right now where a dwarf fortress is a collective of happy drunks rather than the tantrums of old, goblins will lash out easily. Make it so that they are far more prone to snapping and going on murder-sprees. Their vanilla ethics even have no problem with that!
The thing about enabling food production and consumption for goblins is that they'll then be more or less like everybody else. If the player wants to farm, they have dwarfs and humans and more. Masterwork is a mod that focus far more on the mechanical than the roleplaying side of things. Make use of that. Make something fundamentally different.