On the first point: The three lamps can always be controlled separately, which of course leaves many more possibilities open (I think you should also be able to find 3 lamps via Bluetooth, as they each have their own address). I don't really understand the second point: You want to connect the lamp with the bridge and you already have three other Hue lamps connected? If that's it, then I can tell you that of my 80 Hue lamps, I only needed the serial number in one case. Let the app search until it finds the lamps. Then you can press on the lamp found, the corresponding lamp will then flash. Now you can also rename it. The serial number is usually printed on the back of the device or on the lamp holder/lamp. Good luck!