I think the biggest issue with 'avoid getting arrested' questions is that they assume that the person is asking for extreme reactions to trivial situations, thus implying that it's easy to get arrested in such-and-such country. This is easily interpreted as merely a thinly veiled attack on the laws and customs of the nation in question or an attack on how they enforce their laws.
Back in my university days I had friend who had a Chinese professor. She was rather outspoken, but very friendly, approachable and obviously inquisitive. They were having some polite discussion after going over a homework question or something like that, and her professor suggested that she ought to visit China someday. To paraquote, she said something along the lines of, "Knowing me, I'd say something stupid and get myself thrown in jail." He was obviously very upset about this remark (I laughed when she told me about this - we were very young and naive).
The reality is that if you apply common sense, and don't do anything that would certainly be illegal in your own home country, the chances of you 'being arrested' are about the same in both - likely slim to none. As such the questions aren't really much more than noise, due to the obviousness of the answers, or as I suggested earlier, appearing to be just socio-political prods.
On the other hand, 'being-aware-of' questions refer to considerably trickier and subtle situations where doing such seemingly innocent things as trying to tip a waiter/waitress, clapping after a performance, holding your hands behind your back during a religious event or service, can be severely misconstrued. These questions are perceived to ask for more relevant advice on avoiding mistakes in situations that are relatively common in the day to day life of a visitor/tourist. As such, they far more acceptable and relevant to this site.