..But in reality, Shinobi do not practice their jutsu's in the open..
Installing a clan fighting zone will make fights against opponents much more realistic, having to fight on their toes....am i right?
Yes they do... You think Naruto learned rasengan in a clan halls? Or that Neji learned that 360 spin in his clan halls? They've always practiced in areas outside. The fighting zone is meant for people who already know skills to battle against people, mainly it isn't for practicing.
And Hyuuga Hanabi and her father practice their Jyuuken techniques, (barefoot according to my memory) in the open? Where any idiot can watch and learn the secret of byakugan? And all its weaknesses? Neji might have done his in clan halls too, clan techniques, even kekkai genkai, are secret! Sure, a lot of training, is done outside, but not all of it, Hanabi is an example, and im not sure if this counts but in one of the fillers where naruto and co are trying to stop a bomb from blowing up hokage mountain, there are a load of academy students practising their weapon training, and even though they are from unmentioned clans or just normal families, they still practiced indoors.
As for Naruto, he doesnt have a proper clan, even if the 4th was his father, hes dead now so oh well.
I agree with Twitch, if we could work out something, this idea could be really good.