I think there is a way to tie Anakin not being permitted to see his mother and him becoming a Jedi Knight.
Adding a line to the balcony scene where he tells Obi about his dreams might be enough to establish that he must first pass the trials before he can go see her. With this change all of the complaining about Obi not letting him move on would be understandable and it would immensely benefit ROTS.
This would explain his strong fixation with becoming a Jedi Master and his frustration with the Jedi. Because now the situation with Padme would not just be exactly the same as with Shmi, as it is in the movie.
No now the Jedi are also to blame for not letting Anakin help his mother and are denying him their help again, by not making him a Jedi Master.

Also this might help explain why the Jedi or anybody never helped Shmi, though that remains a gigantic plot convenience, especially if I look at Padme: “Slavery is outlawed in the republic. But I, THE QUEEN OF AN ENTIRE PLANET, won’t help the mother of the boy who saved said planet.”
That’s some real gratitude right there…