One of my major changes (If I could make one) would be Padme herself.
First she would have been a queen in title and tradition, not elected. Elected monarchs was a bit of a stretch to begin with, but then having her be elected to the highest office of the planet at 14 was a bit too much for me, evern worse when she said she wasn't the youngest elected-YIKES. I love my children, but I wouldn't let them run the vacum cleaner at 14.
But an inherited title made more sence, THEN after the events of Ep. 1 she returns as a senator, having given up her title and thus ending the monarchy on her planet (the reason, she truely believed in democracy THAT MUCH. I think it would also make a signifigant difference in her character when Palpatine is taking over and the early rebellion sceanes).
Lastly, in ep 3 I would have had her die from truma, not "losing the will to live." and thus weakening the character further. While a bit darker, to say the truma was too great for th med droids to fix would have been plauseable no matter how advanced the technology is. Saving the babies, again we can do that now so not much of a stretch. This also makes Vader's reaction a bit more plauseable (as he might sence the truth in Palpatine's words).
HB I like a bunch of your ideas too.