Past Perfect Vs. Conditional - Beaucoup vs. de Nombreux - Avant que + subjunctive vs. Avant de + infinitive

Question

I have a few questions relating to the B2 writing exercise "What Monster Would You Be" (which was great, BTW!):
without any memory of what I had done the night before.
Kwizbot's answer:
sans aucun souvenir de ce que j'aurais fait la nuit d'avant.
Your answer:
sans aucun souvenir de ce que j'avais fait la nuit d'avant
 
Question #1: Why is it the conditional perfect here and not the past perfect?  The English says I had.  Isn't that past perfect?  
  
before reverting to normal the next morning,
Kwizbot's answer:
avant de redevenir normal le matin suivant,
Your answer:
avant que je ne redevienne normal le matin suivant,
  
Question #2: Why is my response here incorrect?  Why do I need to use avant + infinitive instead of avant que + subjunctive? Is there a subtle difference in meaning?
 
I would know many magic spells
Kwizbot's answer:
Je connaitrais de nombreux sorts
Your answer:
Je connaîtrais beaucoup de sorts
 
 
Question#3: Why can't you use "beaucoup de" here?  Is there a subtle difference in meaning between beacoup and nombreux?  For example, does beaucoup mean "a lot" and nombreux "many"?
 
Merci d'avance de votre aide!  
 
PS - I LOVE the writing challenges and find them the most helpful part of your app!  I would LOVE it if the NEXT button were right under the self-rating system so I wouldn't have to scroll down over the grammar lessons links to get to it.

Cécile Janty-Davies · Accepted Answer

Bonjour Rhonda, 
Sorry about the delay in answering your questions.
1. This is a challenging question to answer, but there was a hint which said " in French literally ' without any memory of what I would have done the night before".
I am afraid that in French it is the realm of the hypothetical, so we cannot use a tense from the indicative mood ( like the pluperfect used in English), which is for things that are happening, have happened, or will happen.
There are often discrepancies with the use of the pluperfect in English and French, and I often hear these on television spoken by educated people, too.
2. Your answer is correct, but we often try to avoid the subjunctive when there are other simpler options, as in using 'avant de' instead of 'avant que'.
3. You could use 'beaucoup de', but 'de nombreux' is so much nicer!
 Thank you very much for your kind comments on our exercises.
As for your PS, please re-post separately, and I'll be able to send it to the helpdesk for your suggestion to be considered.
Bonne Continuation !