All really good stuff, and I've very little to add to it. One thing I don't think has been mentioned; I ask people not to talk to me until after take-off when I tell them it's OK, and the same before landing. You don't need your workload increased by: "Why do you..." at 50ft during a crosswind landing (happened to me once). But I do tell them that if they're interested I'll talk through what I'm doing; some want to know, some would rather look at the view.
I'd err on the side of caution. I HAVE had someone freeze on the yoke when I asked her if she'd like to try flying, only for a few seconds luckily, but it scared the hell out of me. I took up three passengers in a C172 soon after getting my PPL - different handling, wx not great, too much talking, general overload, and as a result I scared one of them (and myself) with a not-so-brilliant landing, and I've probably put her off flying for good. And I feel bad about that.
When I got my PPL I, like you, wanted to take everyone everywhere. Now, a few years later, I'm quite careful who I take up, and what we do and where we go. I hope someone else can learn from my mistakes, not feel compelled to make their own.