Discovered recently that Electric Wizard were kinda dicks back in the day. "At the time, we were pretty bad people. I got arrested for arson of a car, outside a police station. Tim [Bagshaw] went to nick a crucifix off a church roof so we could use it onstage…"
R. L. Burnside killed a man "possibly at a craps game."
Varg of Mayhem Burzum burned a couple churches and killed a bandmate.
I could list other examples, but would like to hear from other people and other music genres.
As someone also in their mid 30s, I think a lot of people really misunderstand how the confederate flag was viewed so casually by many people up until recently. It was always offensive to some, but I genuinely was unaware of that as a teen growing up in the 2000s. It was just an image of being kind of edgy and rebellious but I genuinely didn't think much of it seeing any band using them. Watching Skynyrd or Guns N Roses videos of live concerts? There were "rebel flags" pretty often and I just kind of let it go. It meant nothing to me.
I was in my mid 20s, probably, when it really was explained to me how insensitive that can be. I never associated it with racism or slavery up until that point - and I'm pretty sure that's the same thought that a lot of these bands had. The absolute best thing to do is exactly as you said: own up to it, change your ways, and grow.
Yeah that's how many viewed it in Texas afaik, growing up it was more a "rebel" flag then a, "I'm a racist piece of shit who wants the south to rise again" flag.
Still probably better to leave it in the past.