RueLue: This idea is Tapir's idea, but I think, it is worth an own entry: when editing a == heading all sub-headings with === or ==== (and the same for 2nd level headings with === towards ==== sub-headings) should be editable as well.
At the moment (10-2010) it is not possible to edit only a section at the bottom of a big page (section-#/toc-# over 100; see e.g. the KGS-wishlists) - you must edit the whole page (but that is a bug).
resolved bug for more than 100 headings (new limit is 200); changed behaviour so that sub-headings are included now as well