Yes, they were female writers in ATLA.
I’m not the best person to talk to about Tokka. I’m sure there were moments in S2 and even when Suki arrived there were some further examples of her crush on Sokka. But I agree that their relationship was not really “completed”. The way the creators explain it on the DVD was that Toph’s feelings were just a harmless crush. They didn’t feel it need some big resolution.
As for Kataang…I just spent a good time debating it with a friend of mine on tumblr, so I’m not going go through it again :P Safe to say, there were problems. Virtually anyone will admit that. But I’m still really happy with the canon we got. And I’m perfectly comfortable debating the hell out of anyone that thinks LOK romances are better than ATLA romances. Apart from maybe Lin/Tenzin, that shit is heartbreaking.