Islam critiqued discredits the prophets; Moses unwilling to face Pharao?

In answer to the video "Biblical Insights 12: Pharaoh's Heavy Heart"

Although Moses was hesitant to face the mighty Pharao alone, as anyone in a similar situation would be, although he was complexed by his oratory capabilities, as anyone about to make an important and public address would also be, although he feared he might not properly convince his audience and in addition, that he might be arrested for the crime they accused him of, he never declined the mission and instead asked God to strengthen his speech, fill his heart with courage and appoint his brother Aaron as a helper and associate in prophecy

20:25-36,26:12-15,28:34-5"And my brother, Haroun, he is more eloquent of tongue than I, therefore send him with me as an aider, verifying me: surely I fear that they would reject me. He said: We will strengthen your arm with your brother, and We will give you both an authority, so that they shall not reach you; (go) with Our signs; you two and those who follow you shall be uppermost".

Moses never rejected the mission entrusted to him by asking for his brother to be sent instead, as is the case in the biblical version. Harun's presence uplifted him and, together with the device God gave him to ward off all fear 28:32-3 Moses would be appeased during the encounter and more able to deliver a proper speech. 

In the Hebrew Bible, Moses' fears and concerns following the announcement of his momentous mission is related twice. First at the prospect of ascertaining his prophethood to the elders of the Israelites. The objective was that they should form a delegation to request a 3days leave for the entire community Ex3:18. Moses expresses his fears again, when he was told to confront Pharaoh a second time. His fears are centered around his lack of credibility due to his defect in speech. God says, prior to his encounter with the Israelites to whom he had to announce his prophethood, that He would correct that defect but instead of being comforted, Moses keeps insisting for God to send someone else instead. God wrathfully concedes in part, by appointing his older brother Aaron as his spokesman Ex4:1-16. 

Bizarrely, Moses' second reluctancy, again based on his speech impediment, is placed at the prospect of his second encounter with Pharaoh Ex6:10-13,28-30. Yet Moses had already confronted Pharaoh without ever complaining of his speech defect Ex4:21,5:1-5. That confrontation occured after he convinced the elders of his prophethood with the help of Aaron, and went with them to request the 3 days leave as per God's orders. He meets Pharao at this first encounter together with Aaron, who wasnt appointed by God to go along with him, inexplicably replacing the elders who were supposed to accompany him at that first meeting.

So why did Moses express concerns based on his speech issues before his second encounter with Pharaoh if it wasnt an issue for him before Ex7:1-2? The solution to Moses' speech problem was to make Aaron speak on his behalf, repeating what Moses was whispering to him in front of Pharaoh's court.

On top of the few inconsistencies of the account already pointed, We have now the unrealistic scene of Aaron acting like Moses' sock puppet, a completely unbecoming etiquette in such a situation. It is only following Pharao's refusal to grant the 3 days leave at the first meeting, that we read of Aaron's appointement as Moses' helper to Pharao. His purpose was to allay Moses' anxiety as regards his speech defect, again somthing he doesnt complain about at the prospect of the first meeting, so why is he raising the issue now? The brothers were to go together for a second meeting, demanding the complete freedom of all Israelites.

As can also be read throughout Exodus, it was Aaron, not Moses, who cast down the staff that became a snake before Pharaoh and who held out his staff to trigger the first three plagues against Egypt. However Moses would later direct his staff to the heavens to rain down hail on Egypt. The same staff in Moses' hand would later split, then re-join the sea during the exodus Ex9:23,Ex14:16,21,26. For no real reason, the staff is depicted as passing back and forth between Aaron and Moses, and sometimes in a contradictorily manner from chapter to another. For example, Aaron is the one who allegedly used Moses' staff to turn the water of the Nile into blood but later when addressing Moses at the barren location of Rephidim where the Israelites were encamped, God tells him to take the staff with which he himself struck the Nile with, and hit a rock with it to cause water to gush forth Ex7:19,Ex17:5. Moses would again, later use the staff to defeat the Amalekites Ex17:9.

It is worthwile to note here the fantastic tales surrounding the "magic" staff of Moses in Jewish oral tradition, engraved with God's true name, first taken out by Adam from the Garden of Eden, then given to Noah, Abraham, Isaac, Jacob, Joseph, Jethro who planted it in his garden and no one had since that time been able to pull it out of the earth, until Moses came and removed it easily, thus proving his just claim to its ownership.

The Quran on the other hand describes it in terms unambiguously conveying its normality, lack of any power in and of itself 20:18-21. During his public confrontation with Pharao's magicians, Moses was inspired to

20:69"cast down what is in your right hand".

The staff itself was not the significant factor, it simply was a reassuring tool Moses had the habit of carrying around. By subtely omitting to mention it specifically, the Quran conveys the sense that the significant factor was the will of Allah. In addition, as a testimony of its surgical use of words and precise placements in the relevant context, the Quran when relating the incident where Moses was introduced to the effect of the staff transforming into a serpent for the first time, says that it was not terrifyingly explicit

27:10"he saw it in motion as if it were a serpent" 20:20"a serpent running"

but when the transformation happenned in front of Pharao it was an evident, great and clear snake 7:107 in fact so monstrous that it appeared to swallow the serpents that were produced through trickery, by Pharao's magicians 7:117.