I think the dark elder would be good in kill team. Better then my craftworld elder. Most of the core troops have 12 inch range. I do like your DA fallen ideas and chaos seems fun. I am thinking of putting together a non xenos army. I have always liked the sisters of battle and inquisition. Both the figures and fluff. They are expensive but buying 25 to 30 figures seems a lot more doable than buying a whole army. Necrons seem interesting as well.