nice job on the site. Really like it.
Just some suggestions on problem reporting, etc.:
1. Invest in a copy of vmware, etc., so you can play with various development/qa environments rather than making the code change live.
2. Better error pages. This adds to user experience and can catch and report a whole lot of error automatically. I think there are a couple of php thingies lying around for this that will catch 500 and 404's.
3. A bug report link. You have this forum, but this is like the close button on the elevator. It doesn't do anything but it makes people feel better.
4. Adapt one of the throttling modules (I assume you are using apache) to key off of whether a user is a subscriber. That way paying customers get the bandwidth and performance.
Having run a few very high availability I feel your pain. Support is a thankless task. People only notice you when something goes wrong. They come to associate you with failure.
Anyhow, best of luck.