That's a good list. Thanks. In addition to the minimum criteria you mention, I want to vote for witnesses who work (and use income) to improve the Steem ecosystem. In particular, I'd like to see witnesses using their resources and roles to create teams for development or marketing. If someone does a particularly good job in one or more areas (e.g., funding app development), then I would not expect them to cover other areas (e.g. fighting spam). Some specialization there is fine.