The constitution, as originally proposed, was flawed. The Bill of Rights consists of the first ten Amendments to the constitution. Bill of Rights permits slavery (and permits not letting women vote), so Bill of Rights was also flawed.
No it was not flawed for points you explicitly ignored. Slavery and chauvinistic politics was not against public opinion at the time. During the early 1800's, slavery and women being oppressed were ethically fine. What makes the Constitution so strong is its malleability (and simultaneously its rigid structure) to reform itself according to new discoveries in rights and freedoms. Not according to monarchy but according to the will of the people. It was the first of its kind, outlining such clear importance to freedom of speech, defense and life. Even today you will not find such freedoms in any other country.