In the Name of Allah, the Most Gracious, the Most Merciful.
As-salāmu ‘alaykum wa-rahmatullāhi wa-barakātuh.
At the outset, “Al Ghuniyatut Talibīn” of Sheikh Abdul Qadir Jilani rahimahullah is a hanbali text, as you have correctly pointed out. Hence it is not suitable for a hanafī to read through this text for learning Fiqh.
According to the hanafī madhab, it is permissible to shave the nape as mentioned by Hazrat Mufti Ebrahim Desai Saheb in the fatwa you quoted. Maulana Rasheed Ahmed Ludhiyanwi rahimahullah, a luminary of our era writes about this issue in his collection Ahsanul Fatāwa:
“It is mentioned in ‘Alamgīrī (Fatawa al Hindiyyah) that shaving the “Qafā” is Makrūh.
وَعَنْ أبي حَنِيفَةَ رَحِمَهُ اللَّهُ تَعَالَى يُكْرَهُ أَنْ يَحْلِقَ قَفَاهُ إلَّا عِنْدَ الْحِجَامَةِMost probably Imdādul Fatāwa’s answer was given based on this statement, taking the meaning of Qafā to be nape. The reality is that Qafā can mean back part of head (urdu:guddi) as well as nape. The back portion of the head is included in the head while nape is a separate part. In the section about Masah of nape, Imdādul Fatāwa mentions clearly that Qafā is part of head while nape is excluded from head.
“On authority of Abu Hanīfa rahimahullahu ta‘āla it is mentioned
that it is makrūh to shave Qafā except at the time of cupping…”
Hence back portion of the head is inclusive of the Karahiyyah (dislikeness) of shaving while there is no apparent reason for the shaving of nape to be Makrūh. Hadhrat Mufti Rasheed Ahmad Gangohi rahimahullah mentions, “Neck is a separate part and head is a separate part.
Hence it is permissible to shave the hairs on nape. The joint for head can be felt at the back in line of bottom of the ear lobes. Below this joint is nape.”
(Ahsanul Fatāwā, Vol. 8 Pg. 76)
The mas’alah of Bahishti Zewar which you have mentioned is from Bahishti Gohar. The actual ibarah in urdu is :
ریش بچہ کے جانبین لب زیرین کے بال منڈوانے کو فقہاء نے بدعت لکھا ہے اس لے نہ چاہیے۔ اس طرح گدّی کے بال بنوانے کو بھی فقہاء نے مکروہ لکھا ہے۔Fuqahā’ have classified shaving of the hairs on the two sides of baby beard under the lower lip to be an innovation. It should not be done. Similarly it is makrūh to fashion the hairs on the back part of the head.
(Bahishti Gohar Pg. 115, Allah Bakhsh)
We feel that the above statement from Bahishti Gohar was incorrectly translated, hence the confusion. The urdu statement is clear.
As for shaving the back portion of head being Makrūh according to Imam Abu Hanifa rahimahullah, then it refers to Makruh Tahrīmi.
And Allah Ta’āla Knows Best
Mufti Faisal bin Abdul Hameed,
Checked and Approved by,
Mufti Ebrahim Desai.
 الفتاوى الهندية (5/ 357)، دار الفكر
 Imdadul Fatāwa is compilation of Maulana Ashrah Ali Thanvi rahimahullah’s fatawa.
 Fatāwa Rasheediyyah Pg. 467
 Bahishti Gohar is not part of Bahishti Zewar however is printed as the 11th Part of it.
 وَعَنْ أبي حَنِيفَةَ وَأَبِي يُوسُفَ رَحِمَهُمَا اللَّهُ تَعَالَى أَنَّهُ إلَى الْحَرَامِ أَقْرَبُ كَذَا في الْهِدَايَةِ وهو الْمُخْتَارُ هَكَذَا في شَرْحِ أبي الْمَكَارِمِ هذا هو الْمَكْرُوهُ كَرَاهَةَ تَحْرِيمٍ(الفتاوى الهندية - ط. دار الفكر (5/ 308))