Maybe I'm forgetting a scene from somewhere, highly likely considering any passion I did have for Bleach died with the last arc, but here's my two thoughts on the matter.

1) If you pictured Rukia as a guy, and for simplicity's sake, let's say Rukia's face doesn't change AT ALL, would any of the "chemistry" between Rukia and Ichigo seem romantic still or more 'bromantic'?

Bleach was never about romance, with what little signs of it always being comic relief material. So, why can't they just be best friends?

It's understandably annoying for readers who like to ship people that the core pairing didn't evolve into a romantic pairing, but the reality is Bleach was never developing it towards romance in the first place.

2) Orihime was the only one being romantically aggressive.

Remember the panels about Orihime's clothes? She agreed to the outfit specifically because she was told "Kurosaki-san will be very happy."

I wouldn't be surprised if Orihime was the one to eventually ask out Ichigo after things settled down.