1) You don't need a team, just a subset of an existing team. One person can do it. 2) Same as above. The time-sink in that is quite minimal. 3) We just run it

1) You don't need a team, just a subset of an existing team. One person can do it. 2) Same as above. The time-sink in that is quite minimal. 3) We just run it on an existing mail server. No additional server required. I agree it could heavily depend on the size of the company, but I'd argue bigger companies have an even greater incentive to keep things on their own servers, and probably more resources for doing so. I can't account for any of the other slack features as I've never used it, so I'll have to take your word for it.