Dear Aaron L.,
I'm glad you're enjoying your bin!
If you want to hear the worms talk, you have to stand next to the bin at night when it's really quiet. If the surroundings are quiet enough, you can hear tiny little popping noises--the sound of the worms opening and closing their mouths!
If the worms seem happy to you, they probably are. Generally people who refer to their worms as "happy" are tuned in enough to the process to be able to tell whether or not things are going well.
A lot of people never get any worm juice at all, while a lot of other people get a lot. The amount of worm juice produced is dependent upon the temperature of the room that the bin is in, the amount and moisure levels of the food that is being fed, the amount and type of bedding being used, and the individual ecology of each bin. I cannot reliably predict who will get worm juice and who will not. If you would like some worm juice, you can pour some non-chlorinated water into the bin and allow it to drain into a container.
The little bitty bugs on top of the compost are probably springtails, which are tiny little decomposers that may speed your bin up a tiny little bit. Springtails cannot survive in dry environments, so they really can't leave the bin. If they look like small bits of moving dandruff, they are probably springtails. If you look at one through a very strong lens, you will see an adorable little, big-eyed bug that looks as if it belongs in a Disney movie.
Thanks for the good questions!