I understand that you want to keep "Indiana Jones and the..." for continuity. No problem, it's your edit.
My guess by naming it just "Kingdom of the cristal Skull" is that it would be more like "Raiders of the lost Ark", before Lucas renamed it "Indiana jones and the raiders of the lost ark" on the cover of the DVD.
It would be a way to tell the audience: this edit try to stay as far from Lucas bullshits as possible.