Corruscant as we know it (The presentation as shown from 1999-2005) would not have been feasable with the technology of 1981-82. Corruscant would have to have been rendered as an eloborate minature.
But it would have been lifeless(I.E not many flying vehicles ect ect---and therefore reducing it's sense of scale and size) You also have to remember that Blade Runner debuted barely a year before. Too many fans in 83' would have thought that Star Wars was ripping off Blade Runner( I actually thought Corruscant in 99' ripped of Blade Runner!)
You seem to be making an argument for a Coruscant-like city in the same breath that you argue against it. Blade Runner very successfully created a futuristic city with the effects of the time. The reason the Coruscant of the prequels reminds you of Blade Runner is probably because it deliberately rips off several shots and features of the futuristic L.A. The industrial plane with torches shooting flame, the passenger car landing on an apartment building shot from above, holographic advertisements etc.
A futuristic city in the OT would likely have quite a different tone than the noir inspired city of Blade Runner or the political hub of the prequels. The galaxy is under the control of a despot and this is the center of his activities. The tone would probably be like Nazi occupied Berlin. Some sections would house the sympathetic elite and would be resplendent with propaganda, banners and troops while others would be slums, housing the more aggressive of the Empire's enforcers, the poor and disenfranchised and pockets of resistance represented by graffiti and destroyed propaganda posters.
I think it would have been possible to create a city with a style recognised as distinct from that of Blade Runner. Yes, some would accuse them of ripping off Blade Runner, but that always happens in film criticism. The Return of the King was even accused of ripping off Pirates of the Caribbean in some reviews I read for including a shot of the ghost army charging from a ship. On these terms, a successful argument could be made that Blade Runner simply ripped off Metropolis. Doesn't mean they don't stand on their own or do something different with the same idea.
This is all beside the point, anyways, because ripping off others is surely better than lazily attempting to recreate past successes - which is what they did with the Death Star II.
And any "Wookie battle" would have been like a crass combination of the holiday special meeting Planet Of The Apes.
It barely works in 2005 with the battle on Kashyyk.
I think you'd be hard pressed to conceive of something less tasteful than the Ewoks. I don't actually dislike them all that much, I just see that they're corny and cutesy. A Wookiee army could work if treated appropriately, the trouble is that they were treated badly in the prequels. Firstly, they did the Tarzan yell, which was bad in Jedi and was worse in Sith. Secondly, they were facing off against a not very intimidating enemy, the droids - who actually pass close to the screen and shout "charge" in a high-pitched voice. The whole scene is bad. The wookiees don't stand a chance of shining through.
"Crass" is a matter of execution. It could have been done well.
The costumes were certainly done well, even if we weren't given time to care about the characters behind them.
http://images2.wikia.nocookie.net/__cb20070120142448/starwars/images/d/d1/WookieeWarriors.jpg
Had Lucas and Kurtz never met ---who would been more successful on an individual basis---I don't know about you but I would wager Lucas would have had greater success.
Now this is really debatable. I honestly think the shoe is on the other foot. What Lucas wanted to do with Star Wars seems quite different from what made it a success. The original drafts are a testament to that and the original cut of ANH is regarded as having been a disaster.
Kurtz has said that he challenged Lucas on several of his decisions, and I think it's this combative partnership which resulted in the movies working as well as they did.
The fact that Kurtz was absent when they made Jedi seems to be further evidence of this. It is generally accepted to be lower quality than the rest of the trilogy, which Kurtz worked closely on. The same can be said of the prequels, which seem to be kept afloat only by the Star Wars brand.
On financial success alone, you may be right, but I'd still disagree. Being good at making money is different from being good at making films.
I saw Jedi in 83 ,aged 9 and none of the kids aspired for a wookie battle or for Han to have been killed.
Obviously not, but, then, you can hardly aspire for a movie to be a certain way when you have nothing to go on. It'd be pretty crazy to enter a film and say "Gee, I sure hope a major character dies".
We, on the other hand, have had many years to consider this and also interviews, behind the scenes knowledge, drafts and other details to form our opinions on.