The only way to get the blind headed screws out is to drill them out then use an easy-out. Ive done it a couple of times to remove the steering lock from race cars, while retaining the ignition switch. when you put them back you just have to find some more screws, I think they are 6mm with a 1mm pitch. As for the key code, check the inside of the glove box lid, it's usually written there on a silver sticker. A competent locksmith should be able to find the ket shape for you.

The simplest way to start the car without the key is to detach the switch from the lock, which is done by unscrewing 1 phillips head screw. You can then use the screw driver in the cross shaped slot to start the car. the down side is that the steering lock is usually still on & you cant steer the car.