He has head-butted like a mountain ram though and was docked a point for going low in his last bout. Some people consider Mayweather a dirty fighter. These guys do what's necessary to win but can be perfectly nice people outside of the ring. To equate in-ring behavior to behavior outside the ring is kind of naïve. Broner isn't so bad in the ring but is a thug outside of the ring.
Probably best he walks away then. Seems like you're likely to get hurt fighting if you're not 100% committed. But he's had a better career than most, and he's still young enough that if he wanted to become a... I dunno, dental assistant/welder/social worker? he's got time.
Uh he's had one issue with headbutts and that was because Kessler was also engaging in it. 2. It was actually on the beltline, it wasn't intentionally low and he was docked 1 point for doing it the first time. No warnings, nothing. It was B.S Gennady is dirty too I suppose cuz he hit Lemieux after the belt, an insane shot too at that.
The bottom line is fighting is how these guys make their living and they try to get away with as much as they can in order to win a fight. Their tactics in the ring don't dictate what type of person they are outside of the ring. Ward seems like a good guy to me as does Mathysse. I haven't met either one so I may be wrong.