I'm looking at a house with a fuse box in a bedroom cupboard

Yes

Yes. That's perfectly fine. Just keep it clear and don't cover it with any stuff so it will be accessible at any time.

I don't see why not, aslong as the cupboard can be made secure with regards to children and their wandering hands .. normal guidelines state between 0.45m and 1.25m from floor level. Also ensure nothing can fall inside the cupboard and damage the consumer unit or create any explosive or flammable atmosphere.

Yes that is fine

Its fine although it can be a pain to get to😊 Just keep it clear👍

As long as it’s a fixed permenent cupboard If it’s a wardrobe that could be changed in the future then it should not be in there really as it’s not classed as a perment fixture