As far as Ginny’s Twitter incident, she actually addresses it in this interview:
http://hollywoodlife.com/2013/02/07/once-upon-a-time-spoilers-snow-charming-relationship-ginnifer-goodwin-interview/
I made a comment — purely trying to be funny — that most likely, at 8 o’clock on a sunday night, we’re not going to show a grandmother-granddaughter makeout scenario. I got into a lot of trouble for making that comment. People thought I was being homophobic, but really, I’m just not into incest. In defense of my character, I’m not into the idea of my daughter making out with my stepmother who tried to kill me several times.”
So, basically, she was just saying that looking at the situation from Snow’s perspective, there are plenty of reasons that SQ shouldn’t happen. Which is a fair enough opinion if you put yourself in Snow’s shoes. The fact that they’re both women isn’t what Ginny had an issue with at all.