I go away for a couple of days and look what happens!!
This is fantastic, great work guys. I had completely missed the five-keys-per-level thing, and this explains why level 4 was faulty. I've loaded the original level 4 with the intention of getting exactly five keys, but this is absolutely impossible because you have to go along the top left to reach the lower areas, and this forces the acquisition of more than five. Clearly the rows of keys at the top and bottom must go (and indeed have been removed now).
I'm happy with the edits that have been made in levels 1, 4 and 7. I intend to play the game through to the end of level 7 in the near future, using Michael's latest version, just to be 100% sure it's okay. I'll post here when I'm done.
Regarding the name, yes that's an issue as well, because lots of gamers will erroneously think "Blagger 2 = Son of Blagger". I'll give this some thought.