Updated with your suggestions :-)
I actually lived for while right near the junction in Ealing (saw it
each day from my window) - but I think my original idea of making it
simple was wrong.
As for Camden Town - I'll try to think of a better way to show it :-/

You also ignore national railways and trams altogether, not even showing
interchanges with them -- wouldn't it be worth giving some indication of
such connections?

It depends on whether I really want to make this map useful for anyone
except tube enthusiasts ;-)