Just because a movie does not have an episode number does not make it a better film or suck any less. Crystal Skull for instance, lol.
Star Wars was largely inspired by and was always intended to be a throw back to the 1930's and 40's Sci Fi serials like Flash Gordon and Buck Rogers. Lucas watched these as a kid on adeventure theater on Kron-TV. They were the edited down feature versions though. He later saw the uncut Serial cliffhangers and then He preferred them in that format.
Lucas was a Huge Fan of the Genre. He read all and collected all the ec books by Al williamson and frank frazetta growing up. Later when he got rich in the eighties he purchased Alex Raymonds Flash Gordon Original Artwork from Russ Cochran. Supposedly one of the pieces he purchased and Hung on his wall was 50 thousand dollars. I bet you anything if lucas still has it it is worth several times that now.
The Kurosawa Influence was there early on but largely because Lucas was thumbing through a book Written by his fiend Michael Richie which had a summary of The Hidden Fortress. His 1973 treatment is almost word for word the same as Richies,lol.
Kurosawa Intrestingly enough consciously modeled himself and his Films After John Ford director of westerns.
Lucas would later watch Fords films as an influence on the first star wars movie but originally experienced his vision filtered through the director Kurosawa.