Eh, I think the original Barret was literally supposed to be a parody of Mr. T appearance-wise, and the localization chose to parody Mr T with his dialog. But remake Barret doesn't really look like Mr T anymore so they shouldn't do that. We've only heard like 2 lines so hard to tell what they are doing.
The character should be angry cuz he's got a lot to be angry about, so I dunno how they can get around that. He's had his entire life ruined by Shinra and he blames himself for it and he's taken to getting revenge by blowing up a bunch of mako reactors resulting in innocent people getting killed as collateral damage. The game has Dyne, who is white and had all the same shit that happened to Barret happen to him and he's just as angry and even more violent.
And you got Cid, who makes Barret look friendly by comparison but has lived in relative privilege.
""Yo, jes' think about it… How many people in the world do ya think really understand themselves?" further reinforces Barret as some kind of hyper-masculine cartoon. Not a fully realized person, but a Mr. T facsimile full of weak bon mots."
Uh... this is kinda foreshadowing about the theme of identity in FF7. Both Cloud and Barret aren't fully realized at the start of the game. Barret is lying to himself about why he's leading AVALANCHE and how he's dealing with his own depression is very unhealthy. It's irony. Barret is a person that doesn't really understand himself, and he's coping with his own depression by clinging to a radical ideology and blowing stuff up to shift the guilt he feels.
To me Barret always came across as using abrasive language to push away people who might challenge his coping strategy; but he was a very caring person putting on a facade. It's basically a false identity he's adopted.