A) When left a list and entry again, the User changings (klick on header column) is not away and overwrites again the Project-Settings - A clear function (button or something) must exists to set back to the settings from project (back to default)
B) Multiple sorting not function correct - possible about problem with A)
C) Sort direction not working correct - possible about problem with A)
So, you can expl. set in combination with project settings (default) and user settings (klick on column header) so as in other list systems:
klick 1. time on a header column expl. Name - sort ascending
klick 2. time on a header column expl. Name - sort descending
klick 3. time on a header column expl. Name - delete sorting on this column
klick 4. time on a header column expl. Name - sort ascending - same as when has click only 1 time
klick 1. time on a header column expl. Name - sort ascending
klick 1. time on a header column expl. Surname - sort ascending on 2 fields (name and then surname)
Test the header column sorting as expl. in the free program "Heidi SQL" please - thats a good example, how sorting function correct.