As a new member, and a new supporting member, I thought maybe I'd offer my somewhat fresh eyed perspective.
Having been an admin and a mod of a rather large community in the past, and being someone who believes strongly in supporting the web presences you appreciate, I have to say this community impresses me, both members and staff, and that is why I chose to pony up. If I don't end up staying emotionally invested in it and find myself drifting away after a time, I may not choose to do it next year, and that's normal, web communities are very liquid that way, and you have to just assume that you'll have a turnover from year to year- old members go dormant and stop paying, new members sign up, and if you've got a healthy, strong community, it will still balance out. It's just the nature of the beast.
Here's the thing I love about a paying members area, from a cold calculating management perspective: when particular users start to get cliquey in a thread or subforum, they bond with each other in a way that is far less liquid than the community as a whole. They tend to congregate in those threads or forums with each other to the exclusion of other areas, and that will naturally build on itself. They may become less active elsewhere, less able to be active elsewhere, because they are dependent on the clique that's developed in said subforum. Being cut off from that subculture will be an extremely uncomfortable idea psychologically, and many people will be happy to pay on a continuing basis to stay connected with their chosen group, even when it is technically possible for them all to hang out elsewhere.
Once you've been in the clubhouse, it's no fun to be relegated to the yard; even if all the same people are there- you'll always wonder what they're doing in the clubhouse without you. So personally, I think it's a very smart idea, and one that would tend to retain a lot more paying users in the long run, regardless of what other perks you decide to implement. You can't underestimate the power of the clubhouse.
As to the improved communication issue, perhaps you could frame it as a sort of concierge service, which, in my mind anyway, is more of an added value type thing, as opposed to actually giving higher priorities to paid members when it comes to regular avenues of support, if that makes sense.
Anyway, as a month-old user, I think this community and it's staff does an excellent job of being a welcoming, stimulating place to learn and contribute- I'm already finding myself drawn into potential friendships here, and the value of my education has been frankly priceless. You've really got a beautiful thing going here, and I'd love to see it thrive financially as well. My, yours to keep.
Your thoughts are exactly in line with ours. It's not about alienating non-paying members, because they have the same opportunity as others, it's about rewarding the members who choose to support the forum. This support helps make the forum better for everyone. So I applaud your thoughts, you are right on target.