Hypothetical, but practical question.

If you were a Jedi Master (not a sith) and converted to the dark side, would you retain your Light powers? My friend seems to think you would, but coverting (in my eyes) does not require unlearning how to manipulate the force.

What do you think?

I think that the dark side powers are ten times better than the light side ones. If I was a jedi and did what you described, I would like to keep my dark powers, but I have read in several places that if you have anything to do with the dark side you can be corrupted by it. Ulic Qel-Droma was trying to "conquer the dark side from within" and instead fell to it (or I think it was him)

if you mean that you can't do them after you turned evil, no, you can always do them

if you mean, personally... yes, I would keep them, protection, health and sight are classified under good and they're quite usefull

yeah, Jedi and Sith can both do the same things, they're all drawing from the same force. The difference comes in that the Jedi only use it for "knowledge and defense" and so they avoid all of the aggresive (yet terribly fun!) powers the Sith use with reckless abandon.

Yes, the Force is the Force, is not a matter of what you can do, it is what you WILL and will NOT do.