I love you for this resource. It was relatively quick and easy to absorb and I am saving this link to give to new players.
Btw, typo at the beginning of one of the paragraphs. "Be extra weary of tank..." *wary
@Guy on a bus
Lee Sin inherently falls off late game. It's just how his champion works. As for teleporting around, dodge his Q and he can't jump to you. It's a skillshot, not a targeted willalwayswork ability. That said, Lee Sin is the champ to be to pull off stupid mobility plays with his double jump. On Crucible, if he gets that, he'll have a huge reduction in damage by spending all that money on a support item. This argument could be made for any champ.
He is indeed a menace early on, and a very good duelist to boot. Your best bet would be to ward, ward, and ward some more and play a defensive lane if he's coming. If you're safe enough that he has to Q to you to start the gank, you can probably flash out of it.
I keep saying that Sightstone isn't just for supports, but no one believes me.