I did not say that such terms are exclusively used in such cultures, Travis, read my post again, and if you are sincerely keen on not offending, than don't call your readers bigoted, it is insulting. Just because someone differs from your opinion it does not mean that they are bigoted and you are right. They simply view it one way and you view it a different way.  Labeling people that don't see it like you as 'bigoted' is to seek provocation and it is insulting.

I fully maintain that many people, rich or poor, do not appreciate being approached with some of those terms.  And someone approaching me with those terms still fully gives me the impression they belong to one of those 'cultures' (and others similar to them), based on many experiences.  You rest assured I am not the only fluent English speaker that feels that way.  You should not be so opposed to someone informing your readers about this.  It is fair that an English learner not realizing the fact that that those terms are often associated with those cultures should be aware of it, and let them choose for themselves whether they desire to use those terms or not.

And yes, some of the richest people belong in those cultures such as the drug or rap culture for example, as many of them are the very stars in those cultures.  But that does not mean that the terminology of that culture is acceptable to the average person.  

I simply warned, to only use those terms with caution, being aware of cultural differences and that some of those words are not simply more casual, they often are taken to also be associated with various 'cultures'.  That is a fact, not bigotry, and the readers should be aware of it. 

You are allowed to disagree.  

Even though I'm a native English speaker, reading this article was really interesting.  I always like to learn about different ways our dear language is used all around the world (is that a bit weird?)

Something I noticed that North Americans never use the term "mate".  As a British/Australian, I have to say that "mate" is most one of the most profusely used terms of appellation and can be pretty widely used in all sorts of situations.

Even in a formal kind of situation (like a business meeting),it has the immediate effect of turning a distant/stuffy/emotionally-void scenario into one which is hearty and close.   Perhaps its a bit like the word "buddy"?  I've heard it a lot on US television/movies and assume its equally part of Canadian vernacular.  

Yet I would give a word of caution...

Some of these greetings are connected with 'cultures' eg street culture, certain types of music cultures like rap, drug culture, etc.  

If someone, even a close friend approaches me with hey dude or hey buddy, or hey baby (for a girl), I do not at all appreciate it, chances are I will think they are going to be begging me a bus ticket, try to sell me drugs, or they are hoping for some intimacy if they call me baby, and I don't at all appreciate it.  Instead of sounding friendly they are sounding like bad news.  So use caution!!

Within families also there is a certain culture that differs from family to family, and you have to use wisdom there too.  A regular or an upper class family will likely use different terminology than a welfare family, and these terms are borrowed from the 'culture' that the family members like to associate themselves with.  

If in doubt, stick to the plain "Hello!! How are you, Sally, long time no see!", or "Hi Dan!" Noone will be offended by that.  The best way to show friendliness is by warmth in the tone, rather than breaching the respect that is due by words.  

In doubt, show respect.  Especially to the girls.

Thank you Lydia for your comments, however, there are few points that I politely disagree with.
I would like to start with what we both can agree on:

The key to effective communication among anybody in any language is dependent on only one thing, context. Any expression can be offensive when it is used in the wrong context. As a general rule colloquial expressions should not be used when in professional environments, when talking to superiors, or to people you are unfamiliar with.

I have introduced these expressions, with the hope that learners of the English language will be able to use it as a reference when they encounter it in everyday speech. I want my friends that are learning English to be able to understand what people are saying even if it is not written in a textbook. In other words I want English learners to understand real living English. Not only polite textbook English.

Now onto my disagreements:

The root of our disagreements is likely generational differences. For older generations the use of such expressions may be considered incorrect or perhaps even impolite. However, language evolves and what was once not commonly said has now become normal amongst younger generations.

I disagree with Lydia’s assumption that the aforementioned expressions are exclusively linked to street people, rap, drug culture, or lower social classes (poor people). To imply that only street people, rappers, drug addicts or families on welfare use this language would be a bigotted generalization and a fallacy.I have heard the use of the aforementioned expressions from the mouths of both the rich and the poor.

Also note: "what up homeslice?", "what's happenin' cap'n" and "what's crack-a-lackin'?" are used often in colloquial speaking. :)