Most of these items will be implemented in version 1.8.5 of PixInsight.
1. Work on only the selected icons (process or image)
Right now you can remove, drag and save a selection of icons. Copying/pasting and aligning will also work for selections.
2. Retain the sorting order
If you refer to sorting icons by name, that won't be implemented. Icons are always sorted
positionally: by increasing Y and X coordinates (in that significance order) on the parent workspace. Sorting icons by name leads to important usability issues and confusion; I already learned this years ago, with PixInsight LE. Ordering of icons has to do with the order in which they are meant to be applied, nothing else.
3. Align left, right, top, or bottom edges of selected icons to be aligned
Agreed. This will be implemented. And there will be more options for fine-tuning alignment and distribution of items on workspaces.
4. Allow icons to be copied and pasted (duplicated), while retaining description
Absolutely! And there will be a trash can, too, where icons will be stored when deleted
