Honestly? I've never had to rely on Edge to survive combat. Sure, there have been times I got mauled viciously, and times drain knocked me out in the van as we sped away (BTW, the results when you cast Ice Slick in front of the biker gang that is chasing you are HILLARIOUS!), but I've never had to burn Edge to survive. Mainly because I engage in the idea of "don't be stupid", and focus on making characters without major weaknesses. And I make sure I have both ranged and melee options, so that if I need to hide behind cover and shoot, then I can do that. Also, I always carry flash-bang or smoke grenades if I'm able, because they make getting the hell out of dodge much easier.
In other words, follow the old armed forces creed: Proper Planning Prevents Piss Poor Performance. Sure, things will happen that you don't expect. But if you prepare for everything you can, and you're able to adapt to situations as they develop, then you should never NEED to burn Edge. If you're in a position where you have to burn Edge, either you crit glitched your defense roll, and rolled bad on your damage resistance, or you should have gotten the hell out of dodge long before that.