1. Intersectionality means you can be middle-class white trans male, and you still benefit from the privileges even as you are hindered by the disadvantages.
All whites benefit as a part of that group even as some whites personally suffer.
http://en.m.wikipedia.org/wiki/Intersectionality
And what they mean is that the pressure caused by men and women valuing big tits can be harmful. It's covered by the term
sexual objectification and it's a complex issue. The wikipedia article also mentions the empowerment angle, and male objectification angle, and the ethics of sex angle.
2. I'm a feminist. I disagree with the way you originally stated this, but mostly agree with what you said here.
I disagree with the
the status quo where only some of the people benefit from it, even if the beneficiaries don't actually care and just go with the flow. That attitude is what I'd like to see changed. I don't want to change what people do. I want them to acknowledge that there is inequality, while continuing to do their thing.
The only case that would change is when they feel bad about doing a thing because they now realize it's wrong. Like, maybe rape jokes are bad. Maybe some heroes could be female. Maybe women can be programmers. Maybe in industry events I should assume that everyone is a dev and not a booth babe or hunk, so I don't accidentally insult anyone.
3. Whoooooo boy...
It is self serving if they are female, yes, because wimen as a group are in many but not all ways disadvantageous. I don't know if that's the right word for 'the opposite of privileged'.
It is kinda the opposite of sexism.
Toting a banner of social justice is okay when that's what you are fighting for.