the things you speak of are far from normal and far from ok. That said, I can assure you that it happens every day, between all different members of all different staffs, in all different professions, all over the world, and it's not just you.
I think all members of the team, not just nurses, can get a bit terretorial, and when they find their niche, they can tend to protect it. maybe, it the past, a dragon-like creature swept through the departments you worked in, bossing the nurses about and raising hell, so that when you came along, the nurses were used to having to fight back.. i don't know, it's just a thought. i'd like to think that people aren't like you describe just for the hell of it.
i know that in places i've worked, there's always been a few people like you describe, who you have to really prove yourself to, and to whom nothing is ever good enough for, but i've generally managed to pal up with some nicer people and gain protection that way.. i guess a PA stands out more than 'just another new nurse'.
anyway, i'm sorry this has been your experience, i can assure you that the majority of nurses are not like you describe, and i hope to hell that those few nurses haven't given us all a bad rap in your eyes. (clearly they can't have.. you did marry a nurse, after all!)
oh, and a word of warning, along the lines of what leahjet said.. some of the nurses on this site, are like the nurses you describe, and may bite. I don't think your post is a personal attack on nurses, but some people might. be aware.
and, for the record, i feel awful that i felt i needed to warn you about that, because i'm fairly sure that if i, as a nurse, made the same complaints that you have, i wouldn't get lynched.