1. R2D2 - he wasn't made to speak with humans but with other machines, why would you insert a voice chip in him, I don't know. I don't feel like talking with my toaster.
2. C3PO - it's a protocol droid, he has to be humble and he's great at that. Having some "balls" wouldn't be a good feature.
3. There are swords without handguards, and somehow people fought with them.
4. Blasters - well kinda agree here, but yet again not much was said about them, so we can't really judge them. Like guess what would people 500years ago say about cars? "It's huge, heavy and made of metal, why would I want something like that...".
5. Well some cars dont have seatbelts, neither do motorbikes. I think if you can build a lightsabre you can make something like a flying car in which you can actually sit in.
6. Stormtroopers' uniforms - this is my favourit one. Their uniforms where white INTENTIONALLY, camouflage wasn't an option here because they were supposed to bring fear everywhere they went, the sole sight of them should make their enemies run for their lives.
7. Deathstar - well if they had such strong defense, then why would they think someone could possibly hit that one tiny hole. And the second one was destroyed only because they weren't even halfway finished with it.
8/9. I pretty much agree here
10. Well midichlorians weren't that well described in the series, so we can't really tell whether injecting them is possible.