Very interesting, but I am not sure I understand this passage.
Is Jesus saying we should obey Him because He wants us to obey Him?
Is He saying He won't accept our love unless it is coupled with obedience to His law?
Does the passage preclude showing love through other forms, such as through faith?
No, he's saying that if we love what he is, we will obey Him. Since a major point of Christianity is being like Christ, this is a measure of devotion.
Does the passage preclude showing love through other forms, such as through faith?
Let me put this in a different context: when I married my lovely bride, I promised to honor and cherish her, in sickness and in health, forsaking all others until we were parted by death. Now, if I show derision toward her every time I speak, cheat on her constantly and ditch her when she gets cancer, am i her loving husband? Am I showing her love because I have a piece of paper that says I'm her husband?
Works won't buy your way into Heaven, but as Rich Mullins once said, "Faith without works is like a screen door on a submarine." See the book of james for further clarification.