Movie Daredevil has a healing factorIt's almost certainly just a case of lax storytelling, but I have heard this hypothesis put forward by two completely independent sources (my dad and another friend of mine), so here it goes: In the movie version, Daredevil not only has superhuman senses and agility, but the power to recover from injuries extremely quickly. It's the only way to explain his wildly fluctuating physical condition over the course of the three successive big fights he gets into. (Maybe that radioactive gunk had some of Wolverine's skin in it?)
Foggy Nelson and Elektra will eventually kill the KingpinTo try to save Matt from the constant cycle of violence that he and Fisk go through.
Daredevil's secret identity is Clark KentInspired by photographer-superheroes like Peter Parker and Jimmie Olsen, Clark wanted a piece of the action and to help fight injustice. After all, if those twigs could do it what excuse does he have to be left behind? Needless to say if he wore his glasses people would instantly recognize him so he had to give up the power of sight.