Honestly, if you want to really learn how to write disciplined counterpoint, especially fugues, you should not start out by using such a busy subject. The subject you've posted is pretty chromatic in places and carries with it harmonic implications of secondary dominants and such --- when three or four voices are in full swing later in the piece, it will take great contrapuntal skill to craft perfect individual lines to really make those implied harmonies "work" rather than just sound awkward. My advice is to start with a very simple subject. There is nothing wrong with this, as Bach used quite simple subjects from time to time. Just check out the subject from his crowning contrapuntal achievement, Die Kunst der Fuge.
http://upload.wikimedia.org/wikipedia/commons/9/92/Kunst_der_Fuge.png
Bear in mind, there is nothing really "wrong" with this subject --- it just seems overdone for someone who wishes to write a study in fugue. Start small and work bigger.