This was really interesting to read. And your last point made me laugh ;)

I think Merlin - in comparison to many American shows I've watched - actually does quite well, considering, of course, that Merlin is the one who gets the majority of the screentime, and then of course the big important character of Prince Arthur. :)
I've been quite pleased with the way they've dealt with Gwen and Morgana so far - showing their strengths, weaknesses, abilities and so on - even though yeah, they could have had a fair bit more screentime.