An update on the web server sometimes hanging:
I think that I have identified if not the cause of the issue, at least how to avoid it -- those changes are in the works and will go live as soon as possible.
In the meantime, we have turned on some server configuration that should mitigate the issue if it does occur -- it should take far less time to recover and become usable again. So if you do encounter an issue with the site hanging or returning an error after a long delay, try waiting 5 minutes and then refresh your browser window, it should come back.
Once again, sorry for the trouble this is causing... it has been a very stubborn issue to diagnose and solve.