Ans: Use the zipped executables at following URL to change the address.
(Use LEGO firmware 1.29 or higher for this, and follow instructions to install.)
Explorer.zip upon installation, attach sensor to port 1, run the program and follow on screen instructions.
Ans: Sensor can detect a regular wall surface at angle. The sensor emits IR light and receives reflected light NOSQL the obstacle, and based on that it detects distance to obstacle. If your obstacle wall is at angle, depending on surface finish, some of the light will be bounced back towards the sensor and some will be reflected away (like a mirror). Even if small amount of light is bounced back to the sensor, it will detect it. On the contrary, if your wall surface is like a mirror, most of it will be reflected away, and the sensor may not be able to detect it.
Ans: No, DIST-Nx sensor can not detect RoboCup IR ball.
Ans: Yes, the DIST-Nx sensors are designed to give precise distance to the object.
Ans: No, the IR transmission of DIST-Nx sensors is modulated and focused signal, the signal also not very powerful. It will not interfere with other robots/devices around it. Also, the IR transmission is a 10 degree cone in front of the sensor, anything outside that 10 degree zone does not get the IR light.