Life today is better if you're already established, i.e. have a well paying job, own a home, etc.
Being young in todays world is exponentially harder than it was, say, 40 years ago. Many young people have given up on the idea of home ownership. I'm 26 and I've had friends laugh in my face when I suggested owning instead of renting. It's simply unattainable unless you're in a lucrative field. I'm in Canada for reference (our home price to income ratio is one of the worst in the world).
Not sure where you got this "manipulation is negative persuasion" definition. You can most certainly manipulate people without intending harm. For example, I could manipulate you into buying a bagel instead of a croissant, just to see if I could manipulate you into doing so. No harm is intended, but it's still manipulation.
In a similar vein, people using scientific facts in non-scientific conversations. The amount of times I've heard "well the SCIENCE tells us..." in a moral debate is mind boggling.
That's true, however I do think the meat-only anecdote came from a good place. Him and his daughter had been suffering from clinical depression and a host of other problems for decades and the diet seemed to help them. I think if I was in a similar situation I'd try to let other people know too.
He wasn't "pushing an agenda". He was telling people about how a diet he went on helped him and his daughter. He explicitly stated multiple times that he wasn't a doctor and that his experience was anecdotal.
Sure but people understand the basic transaction (give money -> get milk). If on the other hand they gave you free milk but tracked your milk usage without telling you, I'd argue that's a non-consensual transaction and falls under stealing (roughly).