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)
Deictic (adjective form of deixis, 'pointing') is used in linguistics to designate expressions which explicitly refer to the spatial or temporal relationship between the speaker and what he is talking about. This and that are deictic adjectives or pronouns, and there, then, here, now, whence, whither, thither, hither are deictic adverbs, because they 'point' to objects or places or times from the standpoint of the speaker.
CGEL employs the term 'deictic time' (Td) to designate the speaker's standpoint in time, the time from which he 'points' to the events he is talking about. Deictic time thus seems to be equivalent to what the Reichenbach model calls 'Speech Time' (abbreviated 'ST') or 'Utterance Time'. CGEL's Tr (time referred to) is Reichenbach's 'Event Time' ('ET'), and To (time of orientation) is Reichenbach's 'Reference Time' ('RT').
And when CGEL speaks of 'non-deictive past', it means that the past tense on cheated in he will claim she cheated is not past with reference to Td—the speaker of the sentence is not 'pointing' to an event in the speaker's own past. The event lies in the past relative to To, the (future, hypothothetical) time when the claim of cheating is made.
There's a useful outline of the CGEL scheme here.
Best Answer
Compare these two definitions from the Cambridge Dictionary: the crucial difference is highlighted.
It's also important to understand what award means.
When somebody is awarded a degree, it's permanent: even if they lose the certificate, the official decision still stands, and they still have a degree. In the same way, somebody who has received a Grammy award is a Grammy award winner forever, even if they lose the sculpture.
Grammy awards are an annual event. Somebody who wins an award this year is a Grammy award winner. Somebody who won an award in a previous year (one before the current year) still has the award, and can still be described as a Grammy award winner, but also can be described as a previous Grammy award winner, to make it clear that their award was not this year (before something else). Because they are still Grammy award winners, you can't describe them as former Grammy award winners.
We refer to somebody that used to teach but no longer does so as a former teacher or as an ex-teacher, because they were a teacher before the present time, but they are no longer a teacher.
If a person used to teach you, and now they don't teach you but somebody else does, the first teacher is before somebody else, so you can describe them as "my previous teacher". In this case, it means the teacher before the current teacher.