Several questions here.
First of, since the shinigamis are supposed to be souls, why do they get sick and die, why do they bleed like humans and if that's the case then why do they need gigais in the real world? Why can some of them alter their shape like Kurotsuchi and some are weird looking like the peeps in the Tech Bureau, what's with Capt. Komamura being the only one so far that looks like a giant animal? Several things about this show just doesn't make sense.
When they die in soul society, where do the souls go to since at least the ones in Rukongai are already dead peeps from the real world. If they are souls, how come some gets older like Rukia and Renji while some remain the way they are from when they died. Can the shinigamis procreate? I assume they could since they have people like Byakuya who came from generations of nobles, born into the Kuchiki clan.
Who are the other 3 noble families aside from the Kuchiki clan and where are they now? Can Rukia wear a kenseigan (spelling?) like Byakuya since I read somewhere nobles are the only ones allowed to wear it but I'm not sure if it's only for the head of the family.
I've got more q's but I'll save that for later.