You asked about Paul's reference to the Book of Enoch. 2 Corinthians 12:1-4 sounds a lot like the experience that Enoch had being taken to the third heaven, paradise....there were something like seven levels.
(Excerpt from Book of Enoch)
Chapter 8, VIII
1 And those men took me thence, and led me up on to the third heaven, and placed me there; and I looked downwards, and saw the produce of these places, such as has never been known for goodness.
2 And I saw all the sweet-flowering trees and beheld their fruits, which were sweet-smelling, and all the foods borne (by them) bubbling with fragrant exhalation.
3 And in the midst of the trees that of life, in that place whereon the Lord rests, when he goes up into paradise; and this tree is of ineffable goodness and fragrance, and adorned more than every existing thing; and on all sides (it is) in form gold-looking and vermilion and fire-like and covers all, and it has produce from all fruits.
4 Its root is in the garden at the earth’s end.
5 And paradise is between corruptibility and incorruptibility.
6 And two springs come out which send forth honey and milk, and their springs send forth oil and wine, and they separate into four parts, and go round with quiet course, and go down into the PARADISE OF EDEN, between corruptibility and incorruptibility.
7 And thence they go forth along the earth, and have a revolution to their circle even as other elements.
8 And here there is no unfruitful tree, and every place is blessed.
Anyway, I always wondered, as a JW, why this would be a matter to boast about. When later I read some of the Book of Enoch and it occurred to me that the Enochian stories were maybe highly valued back in the first century and for Paul to have had the same experience as Enoch would maybe sound a bit like bragging or boasting. Anyway, that's my take on it.