I am totally different from you. I am totally convinced, though a Muslim, that I know almost next to nothing about the truth about Islam and about the true nature of the Prophet Muhammad.
If you still know nothing of a man who chopped off the limbs of thieves and blinded them with iron, leaving them to die very slowly, then it's up to you. Perhaps in your heart, you do now, but fear saying it out loud, lest your idea of a god sends you to hell for questioning your "prophet".
You do believe your are qualified to comment on the truth about the prophet Muhammad as you have "read widely on Islam" - various Al-Buhkhari hadith, the Quran,etc. and maybe some other materials. You indeed have the "freedom of believe" to be totally convince of your opinions.
Keep in mind your prophet read widely about nothing. According to islamic scriptures, he was illiterate. Yet, he gave his opinions on other people's religion.
Indeed, I think if a Muslim is asked about this hadith, it would be a real problem. I doubt any could give a satisfying reply as most people would only accept as reference the views of our modern age. I think this is why when Nupur Sharma brought up the "...6 and 9 years...", it caused an uproar in the Muslim world. I humbly apologize that I cannot comment on which side is right or wrong as I don't have a degree from Al-Azhar University.
Most moslem scholars would respond by pronouncing blasphemy on you and calling up a mob to beat you to death and burn down your house. It has happened numerous times that most people stop talking about muhammad in public.
And again, you don't need a degree to comment. People demanding that you have a degree before commenting on your religion often do so to shut you up. If you praise their religion, the same people suddenly don't demand of you to get a degree in theology to back up your praise of their religion.
For this, I believe a Muslim need to put in at least 80 years of deep study on the hadith and the Quran before he could pass an opinion on this particular hadith.
I'm not sure the quran is that deep.
Some of the weird things in the quran include twisting Biblical stories and getting basic concepts of Christianity wrong when commenting on them. The quran mentioned that King Solomon had a demon army, and he threatened the Queen of Sheba with a jihad by his army of demons if she didn't convert to islam.
The quran also mentioned that the Trinity consisted of God the Father, Jesus the Son and Mary the Mother, a clear mistake.