AC main area safe for tourists
I am not an AC fan, but I feel quite safe in AC main red light area. If one stays in the main area, I don't think safety is a concern. AC does not really have any total innocent tourist victim, almost all murders were targeted. I think Pattaya has more innocent killing of tourists than AC, and also Pattaya has lots of mysterious foreigners falling off the condos.
Several years back, I encountered an incident in Pattaya, I was staying on Jomtien Beach, Pattaya, and I was waken up by lots of sirens very early morning about 5 AM, later someone said 2 Russian ladies got shot to death on the beach in front of the hotel, at first the Thai authority was blaming the Russian mafia, but days later, it turned out to be senseless robbery by some Thai thugs. This was the only time that a murder happened so close to me, and it was in Pattaya.
So hang out with the crowds, that's the best precaution. Personally I feel safer walking in main area AC than walking anywhere in Rio, Chang Ping, Manila at night.