2. I'm making up template answers for different queues. Every time you open such an answer you can also change the next state of the ticket after this answer is sent. Is there a way to limit the list of possible states for each different template? Or at least specify the default next state for each template?

You can't do it on a template level (maybe with ACLs, I haven't tried) but it is easily done on a global level in OTRS. Go to Admin -> Sysconfig -> Ticket -> Frontend::Agent::Ticket::ViewCompose Scroll down to Ticket::Frontend::AgentTicketCompose###StateType and enter the states you want the agents to be able to select when composing a follow-up email. -- Lars