Thanks for the link to Hirschman. I'm talking of something slightly different than Hirschman, though. Those who try to build an alternative system do exit the existing system, but they do this for strategic reasons; because they think that this would further their goal more than the alternative strategies. People might exit organizations for all sorrts of other reasons.

I don't think that my 3) is an example of "voice", really. What you're doing here is not that you're trying to influence others directly by arguments or rhetoric. Rather, you're creating a device or a tool which, if generally used will change the social institution in question in the way you want (or so you hope). "Voice" gives me quite different connotations (e.g. lobbying seems to be a classic case of voice).