Are there any clipless pedals anymore that don't have adjustable release tension? I guess I don't know.

The idea is that the pedals will release in a crash just like ski boots. I suppose if you really crank the tension down that may not happen but I'm not sure why you'd want to do that on a typical commute anyway.

Clips and straps can definitely be unsafe if you have the straps pulled down tight (the way they are most effective). That is one reason the industry moved to clipless.