A criminal Thai person would never rob you publicly or even violently. A Thai would "lose face" if that person was publicly exposed as a thief or violent offender. Only drug addicts or alcoholics (including other tourists) are dangerous. This includes in particular the full moon party in Ko-Pha-ngan, the red light district in Pattaya, every crowded discotheque, every secluded place at night which you would also find scary in Germany and avoid. So dont go alone at night to the farthest and most uninhabited corner of the island. Avoid contact with obviously drunk strangers.

Violence by Thais: close to 0%, but still do not travel to remote places where there are absolutely no other people within a few kilometres. With common sense, nothing will happen to you.

Theft by Thais, close to 0%, but be careful: dont leave valuables in your luggage, for example, when travelling by bus your suitcase is unattended. Hotel rooms - dont leave cash lying around.

Theft by other tourists: handbag in discos, valuables on the beach lounger, luggage on the bus.

Basically about Thai men and women. You will probably never see a Thai robbing a tourist on the open street or even using violence. I must honestly say that I sometimes feel very uncomfortable in Germany, at banh stations or on the streets in the dark. I never had this feeling in Thailand. The Thais are very friendly and reserved. You rather have to "protect" yourself from other tourists or should at least be a bit careful.

By "protect" I mean the typical situations like a crowded disco or bar where a thief can easily reach into your handbag. Also on the beach while you are jumping into the sea to cool down. Then you give any opportunist thief the chance to take your valuables on the beach lounger.