If the settings end up the same, of course.... but that is the purpose of using manual, so that you have control over the settings. I think its a little out of line to be suggesting to someone who is interested in learning about photography that shooting in auto is, for all practical purposes, the same as shooting in full manual. And it is certainly out of line to suggest that they are just different paths to the same destination.
I disagree. You seem to be forgetting about Exposure Compensation (EC). Using EC, you can have full control over your exposure in any of the auto modes.
So there really is no difference between using say, aperture priority and +1 EC and using manual and adjusting the settings (same chosen aperture) to one stop over the meter reading. Two different ways to get to the same exposure.
Of course, different apertures/shutter speeds can give you different results with the same exposure, but you can still control that in any of the 4 primary modes.
The KEY is to use and trust your meter.
I disagree with this (as stated anyway).
The meter doesn't know what you are shooting...it only know how much light it's reflecting...and only in the selected metering areas. If you scene (or the metered parts) are not mid-toned (18% grey), then your meter will give you settings that are not technically correct. For example, a person standing in a field of snow, will result in an underexposed shot, if you follow the meter. Same thing with a mostly dark scene, it will end up overexposed with the default meter reading.
The key...is to understand what the meter is doing...and trust that it is always trying to expose for an 18% grey scene. If you meter something that is brighter, you would need to add exposure above the meter. If it's darker, you would need to subtract exposure to be technically accurate.