The sound genin who beat lee was kimimaro though, also the Neji fight in the flashback was when they first became a team, when he didn't know how to open the gates. However Lee was unlucky to have to fight Gaara, also agree with your last two completely. I think you could make an argument for Neji against Naruto as well, because it was literally only one punch that landed and somehow managed to incapacitate Neji
I was talking about the sound genins who were in the forest of death (Dosu, Zaku, Kin)
Well, Lee challenged Neji in almost daily basis, and during his fight with Gaara he stated that he was saving his strongest technique for Neji, and Neji was shocked after seeing how much strong Lee got; but you have got a point, it was Lee's choice to not using 5th gate on him.
About Neji vs Naruto, i think we all know that main character would win almost any fight; but someone like Neji whose sensei is freakin taijutsu specialist, got effected by a genin's punch that easily was not believeble, but also he highly underestimated Naruto, which was the thing that caused hid downfall.