A very late reply, but I will say this. Trust your instincts. If you are not comfortable with something about your dojo, leave. No matter how much you love what you do and the people you do it with it is not worth compromising your own values for.
Perhaps your Sensei is not involved the activities you have heard about, but ask yourself if it is wise to trust someone loyal to people who are. It takes an enormous amount of faith to allow a Sensei to do his job. If you are not steady in that faith then chances are you are not in the right place.
There are other dojos and other Senseis, and though we are all to some degree emotionally invested in our places of practice, it is important not to lose perspective. It can be difficult to see clearly when everyone around you is content and when you are required (as is so often the case) to buy into the myth that whatever you are doing is the best way of doing it. Remember that what is best for one martial artist may not be so for another.
Our paths may cross but they are all by necessity different. Stay on your path and you will find what you need.
Ous.
