Keiko has yet to apply a wind ninjutsu for more cutting force to her thrown weapons, which I fully expect she will be able to, along with seldom used Wind Wall, while also targeting a skill with fewer bonuses typically available. Explosives add to damage, rather than to hit, so still have value. Noburi will get sizeable bonuses in time from jutsu cost discounts. He gets +1/3 to his combat skill from Hozui's Mantle, which comes at half price. It costs 1912.5XP to get WW and HM to 50, which is a 300XP discount compared to the 2211XP for WW 66. If HM also benefits from chakra boost, that's a further 300XP discount over the 2556XP for 71 WW.
Gah, I accidentally closed this on one computer, which didn't save the draft, but somehow it was saved on the other one. Thank you SV and thank you internet. Anyway, I'm very glad that this is the kind of community that can maturely have this discussion. Ya'll rock.