I live in Bangkok and outside the tourist areas i never have a problem. Inside the tourist areas and in Phuket (lived there before) overcharging is a big problem. I never had any violence issues but know many stories from Phuket where they attacked non tuk tuk drivers when they thought they where "stealing" business.
"room filled with rubbish – used sanitary pads, food waste, and even a refrigerator filled with rotten items and crawling with maggots."
We got very different standards then.
"senior Royal Thai Army (RTA) officer (74 years old ??????) shot dead a junior officer (69 years old ????) whom he suspected of stealing belongings from his residence in the central province of Lob Buri.