Was Richie evil?

Depends on what you think the definition of "Evil" is? He was a crack addict and the narcotics had certainly warped his brain and made him far more impulsive. Was he a victim of drug abuse or did he decide upon violence based entirely on his own agency? He was a chaotic criminal who was not nearly as organized as the local Italian mob but still was able to attract numerous henchmen to his cause, which implied that they considered him preferable than the far more powerful (and wealthy) four families. If it wasn't power and money the henchmen were after, they had to be motivated by something else, namely they loved Ritchie and were devoted to him due to some sort of loyalty, charisma of his, or promises of future success. I doubt any of them considered themselves "evil" or would have been attracted to how evil he was. There must have been at least some sort of moral justification on their part, even if it was used to cover up the fact that they were driven by charism or hedonism (he did know how to have fun and throw a mean PARTAY).

Remember when Seagal chases him into the random butcher shop and 100% of the employees took up Ritchie's offer to attack Seagal? It was not even made clear if they were criminals or even knew who Ritchie was. He might have had some kind of hypnotic hold over random people just by being forceful and dominant, which may have inspired them to follow his orders just because they were sick of the alternative. In their eyes, he could have been some kind of an inspiring revolutionary figure rising them up out of a corrupt system (a new direction away from the Italian mob AND the corrupt police department).

As you can tell, I'm endlessly fascinated by the moral philosophy governing the actions of thugs and henchmen in simple-minded 80's/90's action movies.