Thank you, Greg. It helps a lot!

Not sure - I'd need more context. 'low key' generally means 'restrained', or 'modest' or not drawing attention to yourself. A few examples: "I was quiet at the party, I was very low-key and just kept to myself". "He was always low-key in how he dressed. He made sure his clothes were never showy." In your example, I'm not sure what 'stop' is referring to ? Can be several things. Hopefully others can help you better than me.