With your pics, I'm not 100%, where I blew it up, and lost clarity but would say the other "lines" you are referring to, are abrasions or plating issues, they do not appear to be die cracks. What I pointed out with arrows, are die cracks. You keep referring to the cracks in the planchet, these are "die cracks", transferred to the clean, undisturbed planchet, which is the coin you have in hand. I'm sure the highly abraded die, because of the possible clash being scratched away, does weaken the die, leading to die cracks.
-makecents-