Islam critiqued unhappy with divine communications; revelations through angels?

In answer to the video "Muhammad and Merkabah Mysticism"

Divine inspiration transmitted to an individual by an angel is not something unique to Muhammad. Although the Tanakh (like the Quran) recognizes that every prophet receives the ruh/ruach that allows divine inspiration, it is mostly silent on whom the carrier of that inspiration is, except in Daniel's case whose visions, prophetic dreams and inspiration were brought by a third party, who was none other than the angel Gabriel/Jibreel Dan7:15,8:16,9:21. The fact that Gabriel is referred to as "a man" is due to his appearance in the form of a man in Daniel's vision. Gabriel, along with another angel, would later appear to Daniel while awake, but still in the shape of a man. He was sent to Daniel to reveal to him the meaning of a frightening vision he had. Again in

Dan9:21"While I was still speaking in prayer, the man Gabriel, whom I saw in the vision at first, approached me in swift flight about the time of the evening offering".

Gabriel proceeded by transmitting divine revelation upon Daniel.

Moses himself is described as receiving his ever first communication with God through an angel Ex3:2. Other prophets received revelation through angels. In dreams, Jacob was regularily visited by angelic messengers Gen31:11. Same for Elisha 2Kings1:3 or Zechariah's angelic visions later on throughout the book attributed to him.  We also read that the spirit of God descending on an individual is always a pre-condition for prophethood. Even a regular person receiving the spirit of God automatically becomes a prophet Numb11:16-30. In fact we read that when God intends to speak with a prophet, He does so through an angel Numb22:20,35 and it was enough for the prophet Iddo to be convinced of the truthfulness of a man claiming to be a prophet when the latter said he received revelation through an angel 1Kings13:18. When the prophets David and Solomon were visited in dreams by "the Lord", it obviously doesnt mean God physically appeared to them. God visiting these men means He made His will known to them through some means, like the angels 1Kings3:5. Not in one instance is there any prophet who was in this way "visited by the Lord" ever speaking of having literally seen the divine essence. Prophetic revelation through angels, and more particularily through Gabriel, was therefore an already well established knowledge at least among the people of the book before the beginning of Muhammad's mission.

The prophet himself claimed very early on in Mecca as seen from the above verses, that it was an angel who was carrying down revelation to him, not directly through God. The non-believing Arabs, who also believed in the existence of angels but had corrupted it by calling them God's daughters, echoed that claim by challenging him to show those angels of revelation 15:6-7. The Quran would reply to this demand and other similar ones that firstly angels, when they enter the physical realm, only appear in human form and that second, should they ever be sent as per the request of a disbelieving people, then the punishment would immidiately follow.