4 days solo in Sydney

I'm a 27-year-old woman, traveling alone in Sydney in August, on a Saturday recovering from jetlag (New York), and then Tuesday night through Friday. I'm looking for solo-friendly restaurants/bars/cafes. For dinner it would be great to have some spots with a view - either scenery or people-watching, I'm not picky! Otherwise, if anyone has particular cafe's where I can get breakfast, a salad, or an afternoon coffee -- I'd love to try out somewhere that a typical 20-something would stop in for a bite. I've read great things about Quay if I'm looking for a splurge meal, and spots like XS Espresso for a fun milkshake snack. So really, I'm up for anything!