It's something I picked up from video games. For instance in GTA V video game a slang language like "Whats up, homie?" or "See ya, dog!" is used all the time. My question is - under what circumstances can I address a person like this?
From what I know "homie" is more or less neutral. For instance it was used by some hosts of Equal Three show to address an audience. Not so sure regarding safety of "dog" though. Could it be considered offensive?
If you need to "work it out" then you may offend.
"Homie", means people from my home. I.e. people from my city/district/culture/gang. If you are not in their group, it may offend.
"Dog" has a whole range of meanings: from "ugly woman" to "sexually-aggressive man" to "coward". There are many derogatory meanings. The use in slang indicates to someone that "We are so close that we can insult each other"
Don't use either unless you are very confident of your position. In particular let others use it about you first.
This is a cultural/regional dialect, therefore it would sound normal to use within that culture/region with casual friends, but using it elsewhere will be slightly unusual.
Unless you grew up speaking the entire dialect it will likely sound unnatural, because the other things you say won't fit with the dialect, and your pronunciation may be unusual especially with relation to how you normally speak.
Many people use these phrases tongue-in-cheek though with their close friends, so it would work fine in that instance, but people may find it slightly amusing (which is usually the intent).
