I think it would have been more effective, if Schmi Skywalker had died in the first movie (perhaps, at the hand of Darth Maul), and Qui-Gonn took the orphaned Anakin under his wing (aside from the parallels to A NEW HOPE), if they had cast Anakin closer to Amidala's age, about 15, it would have allowed his character a troubled darker edge much earlier in the story, I always had a problem with the boy who would eventually become Vader ever uttering the word 'Yippieeee!'

And Anakin's return to Tatooine in AOTC just slowed the story down, if he was so concerned for his enslaved mother's wellbeing, then why did he leave her in the first place, let alone wait ten years to return and free her?