Couldn't you just cut out the saberdart mystery subplot. Just make it so Obi-Wan is going to Kamino to check the progress of the clone army, and make sure it is on schedule. When he first arrives at Kamino they ask Obi if he is there to check on their progress, and Lama Su tells him they are on schedule. Also when Obi-wan visits Jango's apartment he sees his armor and recognizes it as the same armor the assasin wore on Couruscant. This would make the meeting of Jango seem like a event that was set up by the force. Because if you remember Qui-gon said some meetings are not by chance. This would simplify things alot.
