Re: Kryptonite in first film... Extent of use?
That makes no sense... by your own arguement, it's not like you could sneak up to him with it!
Yes, Superman is usually faster than a speeding bullet... but in several interpretations he has not been faster than a speeding Kryptonite Bullet... obviously the closer the bullet gets, the weaker and slower he becomes, especially if it were a machine gun round of bullets.
I don't know why you think that a kryptonite bullet would richochet off his chest... has that ever happened before? I was always under the impression that his skin could be penetrated by kryptonite, and therefore a kryptonite bullet would cut through him just like it would us.
And I can't see him dodging it, and then running up to the machine gun full of kryptonite bullets and getting 'in the shooter's face'... he'd be at the shooters knees if he tried to get that close to that much kryptonite.
As you say though, there are many other kryptonite weapons that could be fashioned. A net, kryptonite gas canister, kryptonite bomb, kryptonite laser etc tec ... i've even seen x-ray machines infused with kryptonite in a fanfiction (though i'm not sure how that would work).
Superman: Don't be afraid.
Lois: I'm not. Helicopters, danger, go, go, go! Then we'll talk.