Re: Sensei role!
I guess it is really related to the "ryu". If the dojo is bound to a strict style, even guests should try to follow that.
If not, it is sensei's task to help the students find their own aikido.
That does not mean, that they do what they want.
Our sensei even encourages us, to do totally different techniques from what he showed, even in kihon waza - but only if uke resists to the intended technique or if you started wrong or badly.
If I do not manage to do the (intended) technique several times, he would step in and either show uke how to attack in order to let me learn the technique shown, or to show me, what I did wrong.
So if there there is a specific goal in what he wants us to do, he does not allow doing it differently, but if the "other style" works, he would either instruct uke or step in as uke to show when it doesn't and why I have to change here.
So for us there is no style, there is only aikido. That's why we do not have this problem.