Re 2: they just deleted all videos where they couldn't 100% verify things, as a "better safe than sorry" kind of strategy. The overwhelming majority of these videos were fine. I'm not saying there wasn't any problem on PornHub, but I feel the scope of it has been rather overstated, and any platform that allows user-generated content suffers from these problems: YouTube, Facebook, even Hacker News.

Re 1 and 3: I hate to be that guy, but I think "citation needed" is an appropriate request for these. Especially for "3", which seems rather strong.

Re 4: This is a little bit like "would you want your daughter to work at Wall-Mart?" Probably you will have higher hopes for your children than to work near-minimum wage all their lives.