You can switch between the cameras if you set their position and angles this way:

var camera_number = 1;

if (camera_number == 1) // this would be your first camera
{
surv_camera.x = ....
surv_camera.y = ....
surv_camera.z = ....
surv_camera.pan = ....
surv_camera.tilt = ....
surv_camera.roll = ....
}
if (camera_number == 2) // this would be your second camera
{
surv_camera.x = ....
surv_camera.y = ....
surv_camera.z = ....
surv_camera.pan = ....
surv_camera.tilt = ....
surv_camera.roll = ....
}
...........

Make sure to increase camera_number every time when you press the action_key. Use the % operator to set the upper limit for camera_number.

"Player can move when the cameraview is on". That's an easy fix. Add this line of code inside its movement loop:

while (surv_camera.visible) {wait (1);}

Make sure to hide surv_camera when you aren't using it.