I see alot of people ask "why did Lucas make Anakin grow up on Tatooine?" I think Lucas did intend for that part of it because in ANH, Ben tells Luke that "your uncle didn't hold with your fathers ideals...thought he should have STAYED HERE and not gotten involved."
The fact that Luke has kept the Skywalker name in ANH, is because Lucas didn't initially intend Vader to be Lukes father, why go to the trouble of hiding someone if you're not going to change their name, Ben did...and the fact NOBODY involved in the filmmaking knew until ESB that Vader was his father further indicates that Lucas created or incorperated the idea later down the line, after he knew it could be futher explained in a sequel.
R2 and 3PO create big plot holes, caused by Anakin creating 3PO...if Lucas really felt the need to force them into the story, wouldn't it have been more plausible to have Anakin make R2 instead??, wouldn't someone who is supposedly interested in becoming a pilot, or already is a pilot want to create a astro droid for navigation and repairs, instead of a protocol droid which is more suited for a political person like Anakin's wife? Having Padme' own 3PO, and Anakin create 3PO would have solved the Owen knows 3PO plot hole...Ben not knowing R2, is also a bit of a stretch, but probably could have been smoothed over by not having R2 running around in Episode 3 with himself and Anakin, then referring to R2 by name many times....Too bad Ben never remembers owning a droid (R4) either....
Owen is another plot hole, originally he was supposed to be Ben's brother...he could actually have been Anakin's brother, but because Luca made Anakin an immaculate conception without a father, kind of ruins that chance....instead he's Anakin's half brother and doesn't come along until Ep2, and is never really shown having a disagreement with Anakin leaving on a "crusade", or for that matter how Ben even knows about Owen since they never meet until Ben is ready to drop off Anakin's child....a poorly explained and wasted character.