Have your opinions ever been truly changed from a debate?
Sure. Not a literal debate, but a book. I was incredibly antigovernment and pro-democracy until I read The Prince and Discourses on Livy by Machiavelli. Almost a 180 in a year.
Especially The Prince. I still keep a copy of that book with me.
Definitely. I'm not always right and I'll admit it. Life is easier that way.
It has. Several times. Granted, in every single one of those times, it's changed back when new facts were revealed, but I really was quite anti-gun-control for a while, and I really did believe that the free market could solve everything for a year.
On a couple of relatively minor points, yes. (One example being "hate crimes.")
Plenty of times it's set my momentum in the right direction. It was usually when I was a hardcore republican.
Not a complete 180, but debates have often spurred my interest in other viewpoints, many of high I adopted in part.