On the first point, I wasn't making a value judgement about who was right and wrong, I don't know the whole story, just that his life totally fell apart in all the ways that would mess up most late middle age guys. He seems to be a lot happier now and has adjusted to his new life, his kids still talk to him, he's earning a living and I think he has a girlfriend again. The whole chasing after young girls thing seems to have been a midlife crisis.
On your second point, the fact that a younger adult woman wants to have a relationship neither proves nor disproves anything, the fact that she is in one suggests that she has chosen to be.
You also believe that there is a difference between twenty somethings and let's say 18 year olds. Legally there isn't, if you think there should be lobby your MP.
Don't get me wrong I can understand the concern that parents of teenagers have about these relationships, some men can be predatory. I haven't got children myself although I have two nieces in early adult hood who I love very much, I'd hate to think of them being abused or hurt. I guess that sort of age is when parents worry particularly, you don't really know what your kids are up to when they're out with their mates, you just hope they're safe. I'm not into younger women myself, it doesn't appeal to me because I'm not sure what I'd have in common with someone much younger.
This point is a bit off thread, but when I was a fair bit younger I travelled widely and on a couple of occasions older gay guys tried to chat me up. As far as I could work out they used the same tactics a lot of women complain about, trying to impress me with their wealth. Not for me.