Incorrect, you might even slow down your computer slightly by turning off Aero because the Vista basic theme turns off rendering acceleration entirely.
The general consensus is that Aero theme does not affect system performance unless left on while playing games, for obvious reasons. Oh yeah, and the battery life thing, but that can be remedied by turning off those transparency effects.
No.
general consensus is you shouldn't feel much performance impact with a decent computer. windows has had hardware acceleration since 95, it's independent of the theme, and reducing the complexity of what your computer has to process will always decrease drain.
integrated graphics are built into the northbridge, so not only do they slow down the computer by competing with the cpu for ram, the northbridge becomes less efficient via heat.
BESIDES WHICH, THE GPU HELPS BUT THE CPU STILL DOES A FAIR BIT OF WORK. THIS IS IMPLEMENTED MUCH BETTER IN WINDOWS 7 BTW.
i don't know if any fixes have been released but vista relies on the cpu too much when using integrated graphics. aero used 30% processor idling with aero, vs nothing with aero off and 1-3% in windows 7. default windows drivers in all cases.