All I hear is your chain on the last video. There was a recent thread where someone wanted to know what the buzzing sound was when he was in the small cog. The chain links are a certain size and when it goes around a small cog its going to articulate more and buzz a little.
On your other two videos, a couple things to keep in mind for anyone listening. The sounds are very pronounced and louder on video. This includes the act of shifting where you will hear a loud "thunk" and the sound of the trainer itself. Keeping that in mind, it sounds like the chain may be contacting your front derailleur when you are pedaling.