Wa alaikum assalam
RESPONSE TO POINT 1:The verses you have cited of Surah Najm do not provide irrefutable evidence that the Quran was revealed to the Prophet all at once. However, there is
explicit and more cogent
'implicit' evidence throughout the Quran that it's revelation was
piecemeal. As I have noted:
"The disbelievers ask, ‘Why is the Quran not revealed to him all at once?’ [25:32] i.e. as one integral unit (Jumlatan Wahida). Regardless of the obvious charge of the polemics of Islam at the time of the Prophet with this statement which hints at a Prophet of God revealing verses to suit certain conditions, the Quran’s statement clearly denies the insinuations and admits to a well-planned and arranged structure despite its piecemeal revelation." [1]RESPONSE TO POINT 2:It is correct in my humble view to assert that the Quran provides evidence that the Prophet experienced
'the one mighty in power (shadidu'l-quwa)' twice. This is most likely a reference to Gabriel (2:97) who was tasked with the piecemeal revelation to the Prophet.
Furthermore, it is perfectly reconcilable given the verses cited in this response that the Prophet did see Gabriel in his physical form twice (53:13) but also had the Quran's revelation revealed to him subsequently
(as the Quran claims - to his heart) over a period of time (2:97).
There is also further arguable evidence that once these revelations were
'inspired' to the prophet's
'heart', these revelations further manifested to the Prophet in the likeness of
dreams (21:5).
I hope this helps, God willing
Joseph
REFERENCES:[1] THE COMPILATION OF THE QURANhttp://quransmessage.com/articles/the%20compilation%20of%20the%20quran%20FM3.htmRELATED:[2] THE NIGHT JOURNEY - ISRA AND MI'RAJhttp://quransmessage.com/articles/lailatul%20miraj%20FM3.htm