Come talk to us at Facebook. We try very hard in our culture to avoid the bad things you mention above. Send me a message (my contact information is on my profile).
I'm curious, what browser/OS are you using? Your screenshots look different from my view of the site, specifically, the text is either displaced or enlarged in your screenshots, making it look weird.
The spirit of that slogan is more like "Move fast and don't be afraid to disrupt established patterns". The intention is to give employees licence to think out of the box and try out lots of new ideas, without being bogged down by what has gone before. Everyone I've talked to (I personally don't have a lot of experience at jobs outside of Facebook and academia) agrees that Facebook offers you unparalleled freedom to go forth and have impact, unencumbered by red tape and naysayers.
That's not to defend API breakages or incomplete documentation and the pain it causes developers -- I'm not directly involved, but I know that we're definitely trying to get that turned around and fix some of the issues with Facebook Platform.
You're perhaps right. Of course, these people are on things like Facebook, Twitter and blogs and if you can narrow down age, gender, location and medical condition, you might be able to correlate with public posts.
You can also look for specific people in there if you have certain kinds of prior information about them: For example, Aravind Narayanan was able to de-anonymize some part of the Netflix set [http://arxiv.org/abs/cs/0610105]. Maybe that won't translate to this data.
Oooh. This is just begging for a privacy firestorm when someone de-anonymizes the data, which I'm guessing won't be super hard given the kind of medical features they'd need to provide to make this task useful.