I mean ... practically anything is grounds for taking offense in America. Americans are like people who were suddenly told they're allowed to be offended, and now they're on a binge of being offended by everything. I probably wouldn't yell "hey kid" to my waiter at the Waffle House (or maybe I would, if I felt like I liked the kid). But "chico" is a term of endearment. I've never heard it said without some sweetness and tenderness... it doesn't sound the same as "hey kid" delivered in a derogatory way.
Nah. This is like it is in political discussions or online discussions, but in real life, in real time, it is not this way.
You want to use standard and customary forms of communcation, though. You can be a little friendlier, or a little more formal, but it's never good to stray too far if meeting or talking to a person the first time.
However, if you get a bead on the person and their personality, you can adjust your style to theirs is best.
