another possiblity on why the uchiha & the hyuuga clans are noble clans is because they were founding families of the leaf village
and on why the tech in nruto world is uneven,my theory is the the is no need for such things like cars bombs or guns(although it could make the whole show more intersting
). as for cars the are no real roads for them to travel in and out of the village as it is surounded by trees to protect it, also ninja are able to hop around all over the place so it makes the car quite useless. bombs could help in warfare but i think i wouldnt be practical cause it would easily be obliterated by some fireball or other insanse jutsu done by a ninja. as for guns i have no idea why they dont. but as they say "Necessity is the mother of inventions!" and i guess some of the modern stuff are not necessary to the people in the naruto world.