Copyright really isn't an issue. Take the classic episode of Only Fools And Horses where Del and Rodney dress as Batman and Robin - no copyright infringement at all. They were pretending to be Batman and Robin, they
weren't Batman and Robin. Same thing with the Matrix idea.
Besides, if it absolutely came to it, overdubbing dialogue when you've got the characters in paintball masks won't be too tricky
Urban - I think you're underestimating the technical difficulties involved mate! Bullet-time requires a bit of setting up, you can't just throw the cameras in a circle you've got to do it carefully, and the electronic firing could prove tricky. You'll then have to match the resolution and grain of the cameras to whatever format you shoot the movie in. Then you've got very jerky footage, and need to interpolate frames. The CG guy I work with has the software to do this, but when we tested it we had a lot of artifacts. We shot live action on set, which really doesn't work - you need to green-screen the bullet time, interpolate, then composite it into the scene. And as you've got a spinning camera, unless the character is spinning round a stationary background, you'll have to build an entire CG background! You could shoot green-screen then move the entire bullet-time rig onto the set, reshoot just the background, then CG out the rig, but that's not really a great idea.
And then of course green-screen and DV don't work together, you'll need to shoot 35mm or HD, then transfer and digitise. Expensive!
And the wire-rigs, well I've never tried them, but I'm sure you'd need an experienced team to make the action work. A bunch of guys pulling the rig without experience could be dangerous
If you do knock something up, let us see it! I'd also be interested in seeing other work you've done
Cheers
Matt