Muhammad - the best human ever?

My correspondence with my Muslim convert friend continues. Tarek took issue with my examining Muhammad's every action. What was wrong with assassinating al-Nadr, he asked, if al-Nadr represented a danger to the Muslims. 
Muhammad's assassination of al-Nadr
I agree it's not necessarily wrong to assassinate an enemy - if that enemy is so evil and influential that to kill him would without doubt save the lives of many innocents. I'm not sure we can say that about al-Nadr - he hardly seems a Hitler/Stalin figure. And in any case, is assassinating one's enemies really the action of the "best human God has ever created"? We can't judge Muhammad by the same criteria as the rest of us, can we? He's not just a brilliant military leader, is he? He's the best human ever and we must judge him by that criterion.
Prisoners of war
What would I have done, you ask. What do we do now with prisoners of war? Surely expecting the best human to live up to our standards is not unreasonable. He is the best human ever, after all. It's not much of a claim to say "he's the best human but obviously people know better now how to treat prisoners of war". Which is what you seem to be suggesting.
Unworthy actions
We can make the same point about so many of Muhammad's actions which seem unworthy of God's best efforts to create a moral super-man. Marrying a nine year-old? Marrying his step-son's wife because he could and handily receiving a revelation to that effect? Taking 1/5th of the booty of the caravan raids for his personal enjoyment? Telling his men they could sleep with the wives of the men they'd captured. Decapitating hundreds of Jews after the battle of the Trench. The list goes on and on. All of which may be justifiable but seem nonetheless unlikely actions of the best man ever to have lived.
Is it fair to put Muhammad under the spot-light?
You ask me if I'd think it fair if you were to trawl the the minutest detail of the lives of those who inform my ideas. I'd be happy for you to do so, for you know I think it important that we learn something of the character of those whose ideas we admire. (You remember my concerns regarding Azzindani and his "Islamic additions" to Moore's text book that Muslims the world over like to quote as evidence of the miracle of embryology...Something that you have never addressed, by the way.) If it turns out that they are/were lunatics or criminals then I think I'd at least want to reassess any convictions I'd based purely on their hypotheses. (I can't think of any off hand, mind you...). 
But of course, I have never claimed that Darwin or Hitchens or Attenborough et al are divinely inspired or the best humans God has created. I'm not even suggesting they were good men. 
Whereas the claims that are made for Muhammad mean that surely we are entitled to examine his behaviour ... minutely. 
In fact we should examine his behaviour minutely. Any other response would be illogical, since God is "perfect" and omnipotent and therefore if He decides to create the best human, such a man must logically be the best in everything he does or says. Would you not agree?
If I were to announce that Ron L Hubbard (the founder of Scientology) was the best human God has ever created, you'd presumably ask for evidence and want to check out his history and past actions. In fact you'd presumably want to examine his life in detail.
Why is my doing the same for Muhammad any less understandable or justifiable? And if you found actions by Hubbard that suggested he was not the best human ever to have lived, actions recorded by his own supporters no less, you would have serious doubts as to the religion he founded.
Other reasons to disbelieve
If you combine this with the barbaric punishments, the claims to miraculous knowledge which turn out to be debatable at best, the exhortations to kill unbelievers, the uncaring and bullying attitude to the LGBT community, the bizarre promises about Paradise (you've never explained how you can possibly believe some people get to have endless sex with 80 ft magically rejuvenating virgins who have hairless pussies, and legs that are transparent so you can see the marrow in their bones - all this in Bukhari - I've checked), the sadistic promises about Hell that just happen to recycle myths about burning and fire and brimstone which obviously originated when men first saw volcanoes and lava, the apparent copying and misunderstanding of Judaic and Christian myths etc etc then you can perhaps understand the process I have gone through to reach my conclusions. 
PoWs converting to National Socialism? No, you're right. Can't think of any. But then again I don't remember any PoWs being offered their freedom if they "converted", do you?
Forgers?
With regards to the "many forgers" whose reasons you ascribe to tribal, sectarian and national differences, I still don't understand why a Muslim would want to paint their Prophet in a poor light. Especially as presumably the punishment for such actions would be an eternity in Hell. But there we go. Perhaps it's one of those things we shall never get to the bottom of.