Question 1
Answer: A
It is clear that C and D are wrong, so it comes down to removing irony (this part of the factual matrix is not ironic, albeit the 'end result' probably is) and balancing between 'sarcastic' and 'derogatory'. Read this one out loud to yourself. How would you expect the author to have read it? If you set it in the tone/context of the whole piece it is written in quite an opinionated way, perhaps B is accurate but option A works as a more specific (and therefore accurate) answer.
Question 2
Answer: D
The author is more of a 'black letter lawyer' (AKA "Positivist") which is rather clear from a general reading of the text as a whole. This removes options A, B and possibly E. Option C is bizarre as it is not referenced in the text at all. Certainly if you are running out of time, go straight for D at this stage. If not, balancing D and E may be necessary. Take a look at the final sentence (specifically "they punished her for the crime of following the law") and work out what the author means here. The author is, again, being quite sarcastic to the detriment of the German court's decision to punish the (ex-)wife. From this we conclude that the author disliked the conclusion of the Grudge Informer's Case and, as such, we can select the answer as D. Phew...
Question 3
Answer: B
This is quite logical. Hopefully most of you realised that it would be useful to take a note of what the opinion was of all the academics mentioned (e.g. "John Austin = No Morals" as a crude example). This is why it is important to read the question (but, usually, not answers/options!) so you can actively think as you go through your first reading.
This question requires you to be methodical. Start with the first part concerning the case. The outcome of the case would be agreed with by those academics who favour the law following morals, this rules out John Austin and John Griffiths (as we do not really get an idea of which side of this argument he falls on) - note that Dworkin is mentioned only in the introduction, some people have struggled to find him! We are left with B and C.
Now turn to the second part, this requires us to find someone with the opposite view to the first part (the penultimate quote being "“[a] law, which happens to exist, is a law, though we happen to dislike it", be careful on this, people often choose the wrong one because they rush). Run through the options left, Austin and Sally. Much like with Griffiths, we are not given a clear idea of the views that Sally has on this, so strike off option C. We are left with option D (albeit, that was exhausting!)