Salamun Alaikum Chadiga,
Thank you for your questions which I have answered as response 1 and 2 respectively.
RESPONSE 1:
I find no support for this interpretation from the Quran. The 'Protected Book' in verse 56:78 is not directly a reference to the Quran. Rather, the reference in my humble opinion is to the source Book - The Umm-ul-Kitab (Mother Book 13.39; 43.2-4) and the Luh-e-mahfuz (Guarded Tablet 85.21-22) which remains the ultimate source that is with God and which remains protected from any corruption. It is this source tablet which can only be accessed by the very pure (such as those tasked to deliver the message for example Gabriel but not limited to him).
RESPONSE 2:
I am sure we both agree that whenever the noun 'Quran' is used (whether in its definite or indefinite noun form), it still refers to the revelation that Prophet Muhammad received. The noun 'Quran' does not refer to anything else unlike 'book' (kitab) which is a reference to any book or 'the book' (al-kitab) which is a reference to a particular book.
The Quran can also exist as a 'recitation' from memory or a 'reading' from sheets of paper. It is also clear that the Quran (reading / recitation) also existed in the form of a Book at the time of the Prophet as can be seen by the two verses combined.
036:069
"We have not instructed the (Prophet) in poetry, nor is it befitting for him. This is no less than a reminder (Arabic: dhikr) and a Quran making things clear"
015:001
"Alif Lam Ra. These are the verses of the Book (Arabic: al-kitabi) and a Quran that makes (things) clear"
So if one juxtaposes 36:69 with 15:1, the 'reading' existed as a Book (al-kitab) and a 'recitation' from memory (dhikr) at the time of the Prophet at the same time. There are also other examples that the Quran was in written form such as 80:13-16.
080.013-16
"(It is) in sheets / pages held (greatly) in honour (Arabic: fi suhufin mukarrama), Exalted (in dignity), kept pure and holy (Arabic: marfu'atin mutahhara), (Written) by the hands of scribes. (Arabic: bi'aydi safara), honourable and pious and just (Arabic: kiramin barara)"
However, I do think you have a valid point which suggests that further elaboration of 36:69 would be beneficial. This I certainly acknowledge and appreciate. I have therefore updated the article with this in view to assist the readers further. I thank you for bringing this to my attention as a clarification question. Jazak Allah Khair.
Your brother in faith,
Joseph.