incorrect distances and improper spatial relationships to either the milky way or galaxies in their own group
As for spatial relationships, I think you're referring to the rotational quaternion for each galaxy (I guess they have something to do with
Euler parameters), they are for the most part contained in a catalogue file in .CSV format,
NGC-IC.csv, with 10887 lines (and 10886 galaxies). You can read something more about it in the
online manual.
Anyway, like any other big catalogue in SpaceEngine, it's fairly possible for some rotational parameters being wrong.
There's an
Edit mode described in the link above (press numpad * twice etc.), allowing users to change those parameters to match photographic references.
That's exactly why, under the thread "Mods and Addons", there are several "Community Addons" topics where users can share their fixes. There is no specific "galaxy fixes" thread, but a more general "
Catalog Fixes" could be a good starting point to post these fixes.
Depending on the number of reports and/or contributions we could also create such a thread.
In the end, anyone, please feel free to provide better positioning parameters.