Lord Haseo said:
STAR WARS had a lot of plot conveniences
- R2 and C3P0 happen to land somewhere conveniently on the side of the planet where Luke is
The plot was well-constructed. Obi-Wan was on Tatooine. Leia was on a mission to find him on Tattoine. It wasn’t a chance encounter. Since Leia couldn’t reach him, she uploaded the Death Star plans into R2’s memory and sent the droids onto the planet. Yes, they could have landed anywhere, but it’s possible they had knowledge of Obi-Wan’s general location, and in any case, it would be a whole other movie to watch them search the planet for 5 years. At least there were scenes that indicated the passage of time. They didn’t just land at Obi-Wan or Luke’s doorstep in the next scene – THAT would have been contrived.
- Then later when they’re separated they somehow conveniently meet up on the sandcrawler so they can be sold to Owen and Beru
Convenient? The Jawas were droid flippers. They came across R2 and grabbed him. Then they came across 3PO and grabbed him. There were many others too.
- Then the other Astromech poops out conveniently so that R2 can be purchased
This isn’t a plot convenience, it was dramatic intent. Owen could have purchased both R2 and 3PO and the scene would have been over, but it would have been less effective. After the droids went through so much and were separated and then reunited, the possibility they might be separated again pulls on your heart strings a little bit.
- Then Luke somehow conveniently finds part of Leia’s message while cleaning R2
Of your complaints, this is the only one that is a plot convenience. Having one or two of these at the beginning of a story is very standard. The audience usually has no problem with it as long as the storyteller doesn’t make it obviously absurd. The idea to have Luke clean dirt out of R2 and then jar the message out of his memory is a very subtle way to get the story started.