i wouldnt go for beacon.
voting is suspect. simply because some people will get fustrated they are not playing and vote regardless of what the player is doing. the player could be the commander and therefore waiting for the appropriate time to call for reinforcements or near the cap point.
Interestingly the cap zones do change depending on the number of people alive on the server so the two cap thing doesnt apply. I have seen numerous times the last player cap a zone to force more reinforcements....
If the player is AFK or camping (basically not playing the game as intended) then id agree with this sort of plugin. dont get me wrong, this is a problem but im not sure your suggestions work. I have a feeling that slay/slap etc functions dont work in INS which makes it difficult for admins to assist the situation.