I think a big part of having personal character is to not take things too personal and be as nice as possible. If something does happen, then the way I see it is that they had it coming.
For the past fuss ups with people who were being crazy with me, I don't think they are that great of a people to begin with and could build some more character. They are probably just too lazy and have their own mess to deal with. One of my closest friends is too much and she has a great degree of difficulty with social anxiety. She doesn't say that I'm like a brother to her in person anymore from knowing that's going to set me off in the wrong direction.
With girls calling me a brother, I don't like it because I didn't have much of a relationship with my own little sister growing up. It just makes me really mad to hear it and probably is going to be that way for the rest of my life. The only person who gets that privilege of calling me a brother is only my little sister. I just have one and so she's that super special and lucky gal! My close friend kept on pushing it with me and then I ended up driving her to the edge and she ended up relenting. I don't know if she says I'm like a brother to her still to others behind my back, but as long as I don't hear it from her mouth directly then I'm totally fine with it.