Laura,
I almost jumped through the screen twice at you!!! Don't even joke about giving Sammy away.

The humping thing, well, Tex is my only cat that does it/and still does it. Like you, I used to get freaked/grossed out. Now? I just ignore it. I do 'encourage' certain things, like he loves to hump one of my stuffed animals sitting on the bed (Clifford the big red dog, of all things). I just think it isn't that big of a deal, and yeah, he used to do it to my leg at night, too.

The peeing on the catnip, if it was just one isolated incident, ignore it. Maybe he did become soooo unsettled with the 'nip, and lost control.