I feel like Lee would benefit in becoming an expert weaponry user like TenTen.
His lack of long-range attacks really hurts him against Cloyster type of opponents like Gaara and that bone guy who can cloak themselves in spikey armor.
At the very least, he could learn long-range Taijutsu friction/fire attacks like Might Guy.
Isn't it implied - by him being a student and from knowing the Hidden Lotus - that he knows the moves associated with the gates he can open?
Besides that, isn't it against thematics if every character is well-rounded? Like, doesn't it go against the idea of styles, since what gives identity to styles - in some ways - is that they have particular strength. And that carries the idea that in other areas they are not very strong?
Wouldn't the story also lose moral value to viewers if every character has a way to cover every need? I mean, i myself do think such of normal people, that they are made with every talent for any situation they may encounter, but because it is difficult to realise those talents, stories like Naruto work on the idea of limited characters finding ways to make up or overcome their limits, no?