The place of reason

Kant sees reason as the only basis for any universal ethics. This gives little room for human emotions such as sympathy, empathy, happiness, etc. It also means that Kant does not count results or consequences as being ethically relevant. Please address the following:

What are the strengths of basing an ethic entirely on human reason?
What are the flaws of such an ethic?
Develop an example of a universal maxim that we as citizens in a democratic republic ought to see realized in our own country. Choose something that is not already established in the Constitution such as free speech, freedom to worship, or freedom from unwarranted search and seizure.
What role does human reason play in the development and maintenance of this maxim?