Here is a concept to ponder. What if I got a bunch of my friends and we decided to simply walk into your dojo, take it over and refused to leave and cooperate. I decided that I was now in charge and I was going to run things my way or you would have to fight me and all my friends.
Every class we come back and do the same thing to the point that you no longer can train in the ideals and spirit that you embody in Aikido.
What would you do? Turn the other cheek? Stop coming? call the police? what?
What if I don't care to reason with you at all? What if I and my friends simply want to taunt you and bully you every class? do you yield to us and go find another place to train and let us take over the dojo?
What happens if we decide to follow you there and do the same thing? When do you stand your ground? What do you do from an "aikido philosophical/ethical" construct? How do you resolve this?
Ifs and buts, what ifs and yeah buts. Put simply, I would do Aikido. I have faith that Aikido handles violence. Therefore I have faith that a solution is there waiting to be found. Your what ifs above are quite funny. There is no set answer except the one I already gave.
Whichever solution is best. Standing your ground could take many forms for example. It could be teaching you all a lesson, it could be calling the police, it could be leaving and letting you keep taking over like a mischievous zen monk. Who's being led there? I bet a beautiful woman could defeat you and lead you with a smile and a flutter of her eyelids. Gone, mind taken, led.
To see if the priciples I describe can work in extreme situations, (notice I said extreme situations for they are the ones used to try and say they can't) then we would have to look around woildn't we. We would have to look for extreme situations where someone resolved it without force of violence. Have you ever looked for such earnestly? Do such things even make the news? Rarely if ever. Is that because they don't exist?
I'll leave you to ponder this.