I live in Texas, and down here most people smile and say 'hi' to one another--including male strangers to other male strangers--but when I was in New York City everyone looked at me like I was a serial killer for even smiling at people I didn't know. It really is a cultural thing, IMO.
As for walking, there IS an in between. Yes, some people have a hyper feminine "runway walk" where their feet practically cross over one another and some people walk like John Wayne entering a saloon full of bank robbers. But most people, in general, are somewhere in between. I feel that as long as you're not swinging your hips all day long and popping a hip to the side when you stand, people probably aren't going to peg your walk as particularly feminine, even if you don't "spread 'em" and walk on two wide apart lines.
The same for talking. You can be friendly and smile without coming off as either feminine or gay. Sure, maybe you can't be as "omg, that is, like, so awesome!" as you could if you were trying to come off as feminine, but you don't have to be "yo, sup, homie?" with no variation in tone either. In fact, normal men DON'T talk like that. Normal men are somewhere in between Twilight Sparkle declaring that friendship is magic and the Terminator announcing that he'll be back.
Honestly, I wouldn't worry too much about it. Remember in high school when you were SURE that everyone else was watching your every move and it made you really self conscious when, in reality, most people were too busy worrying about themselves to think about you? That's kind of the world in general, IMHO.