Newb question about Cue Lists auto loading into my faders

Each new cue list is assigned to the first available fader. This is normal behavior. 

What are your keystrokes when recording or updating cues where they are recording to a fader?

Update and record cue both create this behaviour 

A cuelist needs to be loaded to a fader to be played back. And when a cue gets recorded or updated it is automatically played back. And because playback needs a fader a cuelist will self-assign to a fader if it currently doesn't live on a fader.

You can't disable the need for a fader, but you can disable auto-playback of a cue. This setting is here: Setup > User > Record Defaults.