Not sure exactly what you're saying there. Was it still running at the end of all of this? Do you know how many teeth the belt jumped? I'm asking this because 1 or 2 teeth off probably won't bend any valves. But if you're certain the valves are bent, then doing a valve job or new head should be no problem with your experience.
On the WP bolts, it's much more common that someone would leave one or two loose, which eventually causes the belt to jump. And this is because there is sideways pressure on the bolts from the belt, which can give a false sense of how tight they are. When I do the final torque of these with an (inch) torque wrench, I always get more turns than it seems like they should be. That's the reason I'm thinking that maybe one or more of the bolts were too loose (assuming you didn't use a torque wrench on them). And are you certain the bolt is stripped - does it spin in the hole without the WP in place? Not trying to second-guess you or insult your knowledge or ability, but without being able to see your Aveo, there's a lot of guesswork on my part.