For your ignition issue, have you tried pressing down on the button with your hand and start the car? I have this issue because the rubber grommet on the pedal is worn out. If it works try this.
http://zilvia.net/f/showthread.php?t=252720
As for the misfiring, check your spark plug tunnels to see if there is rust. If so, grab a wire brush and remove the rust. My SR had this issue in cylinder 1 because the boots on the coilpack is blown out. Also, check to see if the ground wire on the injector harness is grounded to the chassis (mine is grounded under the throttle cable bracket on the firewall).