I humbly offer that the number of sexually active teenagers may be a tad larger than the number of actively homicidal ones. I mean, I can’t back that up - I was a charter member of the latter group but rarely the former.
Heh, my realistic chances of murdering someone as a young teen were higher than my realistic chances of having sex. 
Yes…ish. One implies a deliberate belittling and the other a quaint fantasy. They are heavily correlated but not equivalent.
Nope - entirely different points. The “penetration” point is strictly about the physical act (and was in reference to the previous poster’s description of the act, and was heavily caveated to boot), not about the levels of activity/passivity of the participants or the emotional commitment involved. And it is not a view I myself subscribe to, hence the aforementioned caveats. (Honestly, if I were that Manichean in my views, Dan Savage would come around to my house personally and bitchslap me.)
There is probably a reasonable number of fetishists who fantasize about this exact scenario …