I totally agree with #8, since I have noticed it too. If the doom is coming (and I don't mean Doom 3), or some huge megalo-sized robot needs a driver, they let out the teens. Always 15-years old. Always.
You forgot only one:
11) If there is a harem, it's the shy guy who gets to lead it. Okay, but when the fellow gets blasted to the orbit every now and then by a bunch of wimpy women and does not even get the idea when boobs are fed down his throat, I would be worried if he was missing something between his legs.
Love Hina, Onegai Teacher, and Oh! My Goddess! come to mind easily. I mean: holy jesus! In OMG the hero has 4 ûber-sexy, practically LWO-welcoming goddesess (literally) in his bed, at times in his bath, and still the hero goes like "WAAAH! I'LL CRAP MY PANTS NOW!"
(L like "Legs", W like "Wide..." You can guess what the last word is.
)
Just wish they even ONCE made the hero take the iniative and grasp what is being offered. Hope Green Green has the guts...