Regarding Tatooine I think the Original Trilogy line that has people tending towards having Anakin on the planet is Kenobi stating to Luke that "He didn't hold with your father's ideals, thought he should have stayed here and not gotten involved.
Now that could still easily mean that Anakin and Owen were on a trip and met Kenobi on a nearby planet or station, and while Lars wants Skywalker to go back to Tatooine, he instead goes with Obi-Wan. It would still fit with the spirit of what Kenobi said.
Truth be told, I want to show Tatooine just because in my version, the planet was actually starting to develop commericially with low-level terraforming being considered before the Clone Wars and the Empire's reign completely destroyed any potential of economic development. Basically the planet's a handy visual demonstration of both the costs of the war and that Anakin at the time was giving up a potentially decent life. That this better livelihood was taken away somewhat due to Skywalker's absence is something Lars holds against Kenobi when he shows up with Luke later.