Q21(ii) The phrase "or so we insist" is a comment tagged on at the end of the statement. This comment has the effect of casting doubt on what was previously mentioned. And the author, in doing so, is actually making a point that he does not agree with the statement / thinks the perception is flawed.
Q22(i) This is a 2m question. For the first mark, you are expected to talk about the availability of more tools for communication. For the second mark, you are expected to comment on the effectiveness / efficiency of such tools.
Q22(ii) A commonly written wrong answer is the word "interaction". When you interact with someone, it does not mean there is real engagement or connection. The reference to the previous generation in the text clearly shows that by communication, the author means engagement or connection, not just mere transaction or interaction.
Q23 The phrase "the preoccupied" is tagged on to convey a point of view, a position. It is not merely to describe how busy or how engaged in their gadgets people of this age are. So in your answer, you should convey the writer's judgement too. For example, don't just say that people of this age are busy, which can be a neutral description. It would be better to say that they are too busy.