I'm running a 3rd playthrough now, this time as a female dwarf rogue, and was actually going to romance Josephine this time. I've flirted with Sara a couple of times just to see what her responses are, and she's making comments to the effect cute little ball of something in reference to me. So I'm thinking playing as a dwarf is probably good too if you're looking to woo Sara. Oh and I did do all of the war table apps on the 2nd play through as a Qunari, so that might be a key to finalizing the Sara romance.
On another note, I also started mixing Bull and Viv together in my party this time, and the banter between those two is pretty comical at times. He's surprisingly respectful of her, which I didn't think he would be. (Because most of the time I find her a bit snooty for my likes)