Gotcha actually has several meanings. All of them can be derived from the phrase of which this is a phonetic spelling, namely " [I have] got you". Literally, from the sense of got = "caught, obtained", it means "I've caught you". As in, you were falling, and I caught you, or you were running, and I grabbed you. It's a short step from the benign type of caught to the red-handed type of caught ...
A "gotcha moment" clearly has something important in common with a "Eureka moment": the flash of insight and understanding. But in many cases it is achieved in service to an undeclared motive, which is to capture or defeat an adversary.
slang - Is the term "gotcha moment" familiar? - English Language ...
[Gotcha] wiki Gotcha and I gotcha are relaxed pronunciations of "I ['ve] got you", usually referring to an unexpected capture or discovery. Gotcha is a common colloquialism meaning to understand or comprehend. It is the reduced written form of got you = got + -cha Gotcha can also be spelled as gotchya whereas the related term, getcha, is made by joining the verb and pronoun, get you, with ...
2 I think these best fall under the category of "leading questions" That being said, I don't think there is a word for leading questions with the intent of tricking someone, though "gotcha question" seems to fit your examples well. leading question: A question that prompts or encourages the answer wanted.
0 I feel that 'Gotcha' works and is in the parlance of our times. Although adding 'Ha' before 'Gotcha', in my opinion, reduces the impact.