Re account required: Everyone concerned easily gets an opentechschool.org account, so I'm not sure that's really an issue.
Re Firefox Hello: I'm generally -0 because of the switching costs (and because you can only initate a conversation with Firefox.) There's no plugin required in Chrome, either.
Re Google Docs: A strong -1 here. Docs is a pretty good product IMO, has served us very well in the past, and is widely used among OTS. Because the document is world-readable, users without a sign-in can only comment on it — these show up normally in the document, though, and should be OK to propose agenda items. All others have default write permissions by their membership in opentechschool.org.
I have also added a note to the Community Call doc to that effect.