"Machiavellian" is probably a better term for a book that describes how to manipulate people (for your own benefit).

I don't think a red pilled book would teach you how to manipulate people. I think it would be an attempt to manipulate you towards a specific (red pilled) view of the world.

This rant about radiating happiness towards people without expecting something in return...

The narrator explicitly says he gets something in return though. I think it's important to understand that seemingly charitable acts are never 100% altruistic, and while that's not necessarily a moral judgement, it is still important to understand people's motivations for doing things.

As long as you’re open to their motivation being “it makes them feel good” or “they like making other people happy.” The cynical view is that everyone is fundamentally deeply selfish.

If you go deep enough, you can convince yourself of that, but you lose what Carnegie talks about. You create your own experience of other people by carrying assumptions like that.