It does look a bit rooster-ish to me, especially if the comb is different than the others and already getting red...but, I am not an expert and chickens can surprise you! As for crowing...depends on the rooster, I think---some are real noisy and others less so.
Our Ameraucana rooster's comb started to look very different around 7-8 weeks old - it looks like the tips of fingers placed together in a line, like a child might draw a roosters comb. It still hasn't turned red, and he isn't crowing yet (hes maybe 11-12 weeks? I would have to check the calender), but the comb is very distinct compared to my girls now. To be honest, I can't tell from such a small picture, sorry.
When does the spur on a rooster start to grow? When our Ameraucana hens were little I thought for sure one of them was a rooster because she developed more quickly and was much taller than the rest...but nope, she's just our big girl - still taller than the rest, and very sweet.
I was told by an experienced chicken hand that if the saddle feathers are straight and pointed it's a roo; if they are rounded and curved, it's a pullet. I was convinced one of my chicks was a roo (she was and is tall and rangy) but the experienced chicken hand was right -- this tall rangy chick is laying an egg a day now. Saddle feathers are the ones on the back of the chicken, coming down the side -- like a (duh) saddle. Good luck.