Ion Xe manual fader wing

Fader wings for the Xe are pretty much like previous EOS versions.

Have you checked out the Youtube tutorials?

Example: https://www.youtube.com/watch?v=d4qptPxR9xI

The Ion manual (and supplements) discusses faders on wings and virtual ones as there isn't any difference. They can be subs, playbacks, effects and some new possibilities.

The manual doesn't have a section on Faders... It has information on Faders throughout the documentation.
Also, a few items that are in the manual no longer pertain to the Xe, so you'd also need to read the 50,000 or so supplements to the manual to get a complete picture.

The answers to all of your questions are in the manual(s). . . There's just no good way to look it up.

I recommend starting with
Chapter 16 "Cue Playback", contains Assigning Faders, Changing Fader Pages, Playback Fader Controls
Chapter 20 "Storing and Using Submasters"
Supplement for V2.4.0, "Fader Configuration" initiated a vast change to faders and how they are configured.

I find the bookmarks in the supplement PDF very helpful in finding sections on a specific topic. Not that a truly integrated e-manual wouldn't be nice. It's been on "the list" for some time.

I recommend starting with
Chapter 16 "Cue Playback", contains Assigning Faders, Changing Fader Pages, Playback Fader Controls
Chapter 20 "Storing and Using Submasters"
Supplement for V2.4.0, "Fader Configuration" initiated a vast change to faders and how they are configured.

I find the bookmarks in the supplement PDF very helpful in finding sections on a specific topic. Not that a truly integrated e-manual wouldn't be nice. It's been on "the list" for some time.