I like Mysterio and Chameleon, but I could see why Spider-Man 4 would have emphasis on Vulture and Blackcat.
Honestly, those storyboards and that premise seems really cool to me. Would it have made Mysterio and the like look like Nolan Scarecrow level *******? Sure. But it would be fun to see in the beginning, especially in opening action sequences. I mean, isn't that what we just saw with Crossbones? I would have liked more him, but what was there wasn't terrible.
They would have made Vulture creepy and cool I'm sure. That's probably why they intended to make the villains in the opening weak and "villain of the week" types. To make Vulture a legitimate threat. Look at what Raimi and Co. did with Doc Ock. They took a fat, bowl cut looking, mad scientist dude and gave him some dimension. Their Doc Ock is one of my favorite comic book villains. No reason Vulture wouldn't have turned out well.
Doesn't mean a damn thing anymore though. Hard to believe that stuff is almost a decade old now. I remember being on here when Spider-Man 4, Raimi and Maguire were announced, then a couple of weeks later it got dropped.