Gowether, I will answer your OP in case you come back!
The three examples you give are different issues, and mostly apply to all disadvantaged groups, not just women.
The example of changing rooms is an example of a separate space. Because we have had some success with feminism, women in the UK have been able to create separate spaces for their own use. These include group and discussion spaces, colleges, activity groups, domestic violence shelters, facilities for rape victims, separate wards for women with mental health issues and so on.
That we have created these is a sign of our political strength not weakness. They allow us to organise (separate political meetings about our concerns) , to enter professions and activities we were previously kept out of (i.e. you can't work in this Physics department because we don't have a female toilet), and to protect the vulnerable within our group - the woman who has been beaten, the thirteen year old girl going through puberty who doesn't want males seeing her naked, the woman with mental health problems who would feel worse sleeping next to a male patient.
The IT example is an issue of what does and does not constitute sexism and sexual harassment when in the workplace and/or when attending a work related event. The kind of environment people can expect at work is a legal issue.
The Smurthwaite example is an issue of ideological 'safe space.' It is about the extent to which people in mixed, group situations are entitled to protection against ideas they may disagree with and find personally distressing.
I do not think the three things are particularly related to each other.
'I'd say that there's an assumption of female weakness prior to the fact (does that make sense?). As if we're victims of what might happen even if it's highly unlikely that it will. I'm just starting to feel that maybe we're painting feminism as a collective of women that are likely to get the vapours at any moment and aren't remotely robust.'
Women as a collective are not robust. We have very little power. We are mostly ruled and policed by men. We have very limited voice and representation in the media. We are most of the poor. We are subject to male violence.
If you go into a changing room, presumably with the intention of getting changed, and a person you believe to be a man comes in, the thing has happened to you. You either lose your autonomy over the choice not to be naked in front of random males, or you lose the right to participate in various activities. But it isn't an irrational fear of what is going to happen; it has happened.
I don't feel that girls and women have the right to not be exposed to most ideologies they disagree with in public life. I do think there have to be some restrictions on behaviour in the workplace and in schools in terms of harassment and sexism. I do think they have the right to fully participate in public life without having to be naked in front of male bodied people. I think it is misleading to conflate these things and most people can see the difference.