A couple of thoughts about VML's problems...
Would it be an idea if reps from different 'areas' of parish work (like the music group, readers etc. etc.) were either co-opted onto the council, or chosen as representatives by their group? To reduce the burden on these people, they could be asked to attend PPC meetings only when something relevant to them was under discussion (which in the case of music would either be never, or every time...
) This suggestion emerges from some behind-the-scenes correspondence I've been having about our own difficulties -- hope it's helpful.
As regards the freelance liturgists, that's also tough to deal with. However, it might be an idea if you had a quiet chat with the person concerned and introduced her to GIRM -- in particular the bit about how the psalm should be performed. You can say that it's a bit restrictive, but those are the rules we ALL have to follow, like them or not... (I think you'll find the relevant bit elsewhere on this forum, otherwise drop me a private message and I can give you the reference).
Not contacting the other members is really a bit inconsiderate: the line we try to take (as I've mentioned before) is that everyone has equal weight in the choice of music, and everyone is equally important -- whatever their musical ability or lack of it. There are no 'stars', in other words, so we have to be patient when someone takes a long time to learn a particular psalm, and remember that years ago even the most 'professional' of us would have taken just as long! If you can 'sell' that as an ethos for the choir, you might be able to make these two see what they're missing -- the input of older members is very important to any music group, because they provide a useful 'reality check'. If they like it and can cope with it, there's a better chance that the older part of the congregation can also cope -- and as musicians we are, after all, supposed to be serving the congregation and the church (as well as trying to 'educate' them...
)
On Mass settings our group has a rule that we change the Mass setting only when the season changes (or when we're in Ordinary Time and have been doing the same one for about 10 weeks...
) We don't think it's fair on the congregation to keep chopping and changing -- but that may be because we're being TOO considerate. I'd be interested to hear what other people do about this one. In VML's case it might get you off the hook with this particular problem, though.