The entire premise of your discussion hinges on the hypothesis that you believe that Lee needs a nerf when he really doesn't.
As you would have others believe, is that Lee is overpowered because of his versatility. The problem isn't that Lee is too versatile, it's that other jungler options are NOT. We need more diversity in the jungle and more versatility, not less!
Spell vamp on Lee is unique among other AD assassins who do not get this benefit, but aside from that matter, the spell vamp benefit still requires Lee to activate 80 of his energy. It was earlier stated that Lee would not readily activate the Iron Will in the heat of a battle because it would take from his energy pool, and it could hinder Lee's use of his other, more important skills.
If Lee doesn't benefit from the skill in battle, then you want to nerf it so he has a weaker sustain in jungle only. Nearly every jungler role has innate sustain in their kit design to combat the fact that junglers are constantly taking damage from their camps in order to farm, which no one else does.
If every jungler has sustain built into their kit, why would you argue for removal from only one of those junglers?
the answer is simple: you're trying to gimp a champion. so just stahp.
Lee has been released for something like 2 1/2 years already and if you haven't adapted to him by now you should probably just choose another game instead of trying to get some peoples' favourite champion nerfed.
Please just learn to play against Lee, find out what works and what doesn't work for yourself instead of resorting to asking for nerfs because we all know that this is the least viable solution for you to deal with this problem in the immediate future.