4. Can the UPS work as a Surge Protector ?

Answer: The main function of UPS is to power backup the systems, means when the AC power line is failure the UPS will act immediately to supply the voltage for continuing to use the devices (Loads) which is connected behind the UPS. Since the UPS is installed in series with the electrical system and the load has connected behind the UPS, so when Extreme energy of Surge is occurred it can be damage the UPS itself then remain surge energy can also damage the Load which connected behind the UPS as well.
Note: Voltage Stabilizer, Voltage regulator, Line Conditioner are unable to protect the surge with the same working principle as UPS.