Salaam Wakas,
The quote you presented under the "From Tradition" heading, does not support the traditional view in my opinion. Traditional view holds that Muhammad was infallible and by extension all God's prophets were infallible. It is very very difficult for us mortals to judge. When does a mistake become a sin? I believe God considers the purity of the heart and the intentions in all kinds of extenuating circumstances rather than just considering only the outcome.
To answer Kristina's question, " was Muhammed perfect?". Perfection is not an attribute of mankind. At best, it can be said that man has been, is and will always be in the process of attaining higher and higher levels of existence.
Peace,