OK, your post reminded us of an important item we meant to add to the guidelines, but forgot: this is an AWZ discussion; please don't bring in other soaps/comparisons to other soaps. In all our time in this fandom, we've never seen those kinds of discussions result in anything but frustration on all sides. Please keep this AWZ-focused.
(Also please check the community guidelines about LJ-cutting your posts -- that's just good IJ etiquette so readers don't have to scroll and scroll down their flist.)
Now as for Ben... *glares* Yes, I agree he needs to catch a clue. For one, she is a very young girl and it's quite obvious that she's crushing on him something awful. It strains credibility to think he has noticed *nothing*. And I will not accept any "but I'm just treating her like my sister" excuses from Ben Steinkamp.
I am also annoyed with how Show is ignoring the very blatant moments that in other coupes would be the heartbeat moment -- whether it's watching her in the ballet room or seeing her skate, there are so many times that there should have been some inkling that she is a woman. I think it'd be more believable if he *did* have those feelings and then checked himself because she is so young. It's the cluelessness that makes me bash my bagplant more than Ben's actual behaviour.
And that's where I think his behaviour differs from Deniz's. I don't agree that Deniz was ever that guileless in his flirting with anyone. He knew exactly how to turn it on (see awkward party at Nina's house). From the moment he walked into No.7, he had that cocky awareness of what his pout was worth. Ben, on the other hand, works that pout (especially with Ingo lol) but he doesn't seem to know its value. And that's hard to believe.
But as for cultural norms, I do have to warn you to stay out of the South. In Texas, the good old boys are the politest, most considerate men you'll ever meet. And seriously, just RUN AWAY!