Puck.JS connection to Bluno Beetle

I can't find too much information on the Bluno Beetle in my quick look, but Espruino can communicate with basically any Bluetooth LE device so you should be fine.

Obviously I don't have one here to test, but going by the code that's at https://evothings.com/doc/examples/bluno-helloworld.html

It seems that you can just connect with the Puck.js and write to characteristic 0000dfb1-0000-1000-8000-00805f9b34fb so something like the following should work:

var gatt;
NRF.requestDevice({ filters: [{ namePrefix: 'Puck.js' }] }).then(function(device) {
  return device.gatt.connect();
}).then(function(g) {
  gatt = g;
  return gatt.getPrimaryService("0000dfb0-0000-1000-8000-00805f9b34fb");
}).then(function(service) {
  return service.getCharacteristic("0000dfb1-0000-1000-8000-00805f9b34fb");
}).then(function(characteristic) {
  return characteristic.writeValue([0x01]); // or 0x00 for off
}).then(function() {
  gatt.disconnect();
  console.log("Done!");
});

The radio module on Puck.js is CE/FCC/etc certified, and since that's the only emitting component we self-certify Puck.js itself. So short answer - yes, it's CE certified.

I'm not 100% sure what you mean by EMS-proofed, but as part of the CE testing for the module there's a bunch of electromagnetic testing, and since there's nothing conductive on Puck.js's exterior I'd be confident in it even in pretty electrically harsh environments.