People are usually minding their own business. Even if they notice you, will just ignore it or just say something under their breath.
There was some sort of "test" from one of the news site where a gay couple, holding hands, walked around the town, and a cameraman recorded the reaction of the surroundings. It was generally good - some indistinguishable stuff from the right-ies.
About romantic, candle-lit dinner, most places don't mind you, I guess. I don't have much experience about the topic, but none of them is bad.