Dude, the topic was four months ago, he's probably got it figured out by now

But even, so I happen to disagree. Once you work up the gets to actually try, I find that wallflips are easier than most flips. I would much rather do a wallflip unspotted than I backflip unspotted.
Also, I feel that it is a neccesary lesson to hit the dirt a few times. If you're two scared of some bruises, you'le never get anything done.
It may be
better to learn in a gym, but not many people have gym's available for them, so practising outside is a good option.
As for the paralyzation part, if you aren't willing to risk injuries you shouldn't be doing parkour in the first place.
*That was not meant to be taken as just go out and randomly try flips either. They can be dangerous, so make sure you read some tutorials, and practise things that lead up to it. If you do try it, my advice is to absolutely COMMIT.