  We evaluate the magnitude of two important mesoscopic effects using a
realistic model of typical quantum dots. ``Scrambling'' and ``gate effect'' are
defined as the change in the single-particle spectrum due to added electrons or
gate-induced shape deformation, respectively. These two effects are
investigated systematically in both the self-consistent Kohn-Sham (KS) theory
and a Fermi liquid-like Strutinsky approach. We find that the genuine
scrambling effect is small because the potential here is smooth. In the KS
theory, a key point is the implicit inclusion of residual interactions in the
spectrum; these dominate and make scrambling appear larger. Finally, the gate
effect is comparable in the two cases and, while small, is able to cause
gate-induced spin transitions.
