It may be that the battery on your controller has failed. Many repair shops can replace the battery for you. Or, if you are familiar with electronic repair, you can find many guides on this site to mend it yourself.
Clean everything else, most especially the vent hose or tube. If that doesn't do it, then you need to call in an appliance repairer to address the problem.
The lights are there to display the status of your Dot, so turning them off completely isn't possible. Since Amazon knows you'll be using their devices at night, the lights...
If the battery was working well when disconnected, then either its connections are dirty or a cable is about to break off. I mention the cable because disconnecting often can...
It was probably set by the previous owners. Either try to contact them or keep spamming the "I forgot my password" button, and then a master key will pop up....
Make sure the text is entered exactly as described. It's likely that you have a space in front of one of the names, where there should only be a single...