Hi rskedgell, no there was no actual signs on this road prohibiting pedestrians. I just noticed that it was a dual carriageway with no pavement ("sidewalk" in osm speak).
You are right though about the legal aspects and I'll remove that particular tag. There are some other dual carriageways that I tagged this through streetcomplete so I'll go through them all.
Thanks for the clarification.

Yes, that area should have been "pedestrian" no idea how that happened. Just re-downloaded the area to edit, but noticed you've just fixed my mistake. Thanks.

Ah, fooey! That gate was supposed to have been placed on the road not the boundary! I'm surprised that Josm didn't come up with a validation warning. I'll have to add that to the software.

Yes, you are completely correct. The curse of the auto-complete has struck again! I definitely typed in "12" but the computer thought for some reason that I meant "122" (possibly because I recently used 122 as a post_box ref).

I've corrected it now.

Like you, I am undecided about the best tagging scheme. Previously I had used "alt_name" but then I noticed that somebody had used "name" for another building number and "occupier" for the name of the department - which to me looked like a good idea. If they are locally referred to as "blocks" then by all means add "loc_name" tags, I won't be offended if my edits get edited!

Thanks for letting me know my mistake.