RE: jigging for pike
drag would prevent the cause of the fish just snapping it instantly, in many of my experiences with pike, i've only landed a few with just mono on tip ups fishing for perch or bass, and lucky got them in the corner of the mouth.
If the pike gets it in anyfurther he'll most likely snap it, specially if its one in the 30 inch and above range.
You'll higher your odds of landing with short steel leaders of about what? i'd say atleast 10 inches.