1> akicks - Unlike akills, akicks are designed to be permanent, so an expiry would defeat the purpose. other wise the syntax is as you sugested: /cs akick #channel add mask reason. If you want the user temporarily removed, use a timed ban: /cs help tban or use the cs_tban_address module.
2> mlogout - Channel security rule #1, don't give out the channel password ... period. If you want some users to act like founders use a module: cs_autoowner. IMHO, Channel founders should not have access to the ability to make other users re-identify. Afterall, it's just a channel, identifying is a GLOBAL event and affects the user in ALL channels not just the one and Channel Founders just don't need that much power. Services Admins however already have the ability to /cs logout the entire channel.
3> Nothing stops the users from re-identifying and doing it all over again.