Thanks for the feedback on the missing tag information. I'll fix it for the next release.
Berries and Pears are behaving as intended as they offer both sustenance and hydration. I'll look in to whether there is a better way to handle this though.
Potatoes are indeed a food ingredient. Have you ever eaten a raw potato?!
This mod works fine with 663 - It's probably a problem with your installation. I'm guessing you used the rar version rather than the smod version? This can happen if you extract incorrectly.
The mod shouldn't be causing stuttering. Unless your game stutters when hearthlings eat too. The drink mechanic is a rework of the hearthling eat mechanic. I would be grateful if you continue to monitor an report any reproducible issues you find