Yeah her philosophy is weak, but – assuming your paraphrase of your professor’s argument is accurate – not from such straight forward cut and dry rebuttals. The main problem is with the usage of “best”; it’s more accurate to say people are motivated from self-interest not so much what is “best” for themselves, although they may backwards rationalize that their actions/choices really serve their “best interests” – which results really may or may not show as a benefit to them. What each individual believes is “best” for them obviously varies, and most people don’t really know what would be in their best interest (e.g. coke addicts, people constantly putting themselves in debt, etc.), but rather they driven by self-interest and desires. To know what would be in the best interest for an individual would take a great deal of self-knowledge, self-awareness, and strength of mind and courage needed to observe their own motives honestly without lying to themselves and trying to hide from personal flaws – such a person would be extremely rare.
Anyway, almost done reading The Daemon by Anthony Peake; it’s mind blowing stuff. Look it up if you want, or not.
As for Panchadasi’s stuff on the astral, subjects like this is not so much a matter of believing or not (that goes nowhere) but rather finding out for yourself through personal experience. Panchadasi’s writings is over a hundred years old if I’m right, and not up to date with latest findings. If you want to approach the subject from a scientific angle check out The Out of Body Experience: The History and Science of Astral Travel by, coincidentally again, Anthony Peake.