1.
The first question is about the tense we should use after "as soon as". In a sentence such as this:
I had left when the phone rang.
you need to use the past perfect in the second clause to show which action came first and which – second. However, when you use “as soon as”, the sequence is clear and it is normally a matter of preference which one to use, so both your examples will be correct. In American English the preference would normally be past simple. The past perfect would emphasize the fact that one action was complete before the other one occurred. (an explanation given in Grammar for Teachers by Andrea DeCapua)
2.
In the second pair of examples they are both correct again. It is unnecessary to use past perfect because the time is mentioned and the sequence of events is clear. Also, the actions are described in the order in which they occurred. You can use the past perfect if you want, to emphasize that one was before the other.
3.
The third question was about the sentence
He said that the moment he first met her, he felt something special and began to keep a diary.
The actual words the man said must have been:
"The moment I first met her, I felt something special and began to keep a diary."
When you report his words and begin with “He said”, the entire phrase shifts one tense back and becomes:
He said that the moment he had first met her, he had felt something special and had begun to keep a diary.
Although this is the grammatically correct sentence, it is very common that the past simple does not become past perfect in indirect speech. When reporting, native speakers tend to make present tenses past ("I am studying" - "She said she was studying") but very often do not care to make the past tenses perfect, as grammar books always teach us we should.
That is what makes both these sentences correct: "He said that the moment he first met her, he felt something special and began to keep a diary." and “He said that the moment he had first met her, he had felt something special and had begun to keep a diary.” (have a look at the end of this page)
In sentence 1, I would prefer using past continuous (he was holding the hand ...), because using past simple will make it sounds like he held some white girl's hand habitually. (Note: If you change because to after, I think held will be more appropriate. It should also be even more appropriate than past perfect, in my opinion.)
To explain why using past continuous (or past progressive) is preferred, here is the closest entry I can find in Practical English Usage by Michael Swan.
422 past (2): past progressive (I was working etc)
3 past progressive and simple past: 'background' events
We often use the past progressive together with a simple past tense. The past progressive refers to a longer 'background' action or situation; the simple past refers to a shorter action or event that happened in the middle of the longer action, or that interrupted it.
As I was walking down the road, I saw Bill.
The phone rang while I was having dinner.
Mozart died while he was composing the Requiem.
In sentence 2, if you have this sentence alone:
Fans (queued/were queuing) overnight at a Hollywood music shop for the chance to get Lady Gaga's autograph.
I would say that either queued or were queuing can be used, depending on the way you want to narrate the scene. If you were a journalist writing it as a news, I think using queued would be more appropriate. However, if you were an anchor reporting the news, using were queuing would be more appropriate. This is because, according to my observation, TV news anchors usually use progressive tenses to arouse our attention, to make us feel as if we were in the scene of the news they are reporting.
However, when you gave the full passage,
Fans (queued/were queuing) overnight at a Hollywood music shop for the chance to get Lady Gaga's autograph. While they were waiting, Gaga saw their tweets. She immediately ordered 80 takeaway pizzas and sent them to her fans in case they were hungry.
I changed my preference to queued immediately. The reason is because it will provide the background (or the first reference time [ref.], if you prefer) for the whole story. Besides, there is already one use of the past progressive (... they were waiting, ...) as the main event of the whole story, which is sufficient for a news report.
Best Answer
We use the infinitive (not the present tense) after did (the axillary verb) in questions and negative sentences. This is correct.
We usually use the past form of the verb in the affirmative sentence. This would be correct.
But you can use emphatic did with the infinitive in the affirmative sentence in some situations to emphasize the action.