I installed a new SSD into my MBP last week. Before doing it, I forgot to deauthorise the old disk. To save me from swapping out the SSD again, is it possible to remove that computer manually from iTunes? One can manager devices in iTunes, but for computers it seems you can only remove all.
You have 2 options (since it seems no one actually answered this question, I will). You can pop the old HDD back in a deauthorize it, provided you haven't erased it yet. Or you can remove everything and start reauthorizing. That's really all you have.
As to the whole debate, I think the idea is the spirit of the law. My wife and I share my ID because it's easier and more convenient, but I don't share my ID with any of the rest of my family. If you had 5 kids, all grown and out of the house, and they're all using it, I'd say that's far more suspect than if a husband and wife use it, or if a family living under one roof all use it.