Clutch Cable Q

Brand new motor... drove the car for less than 2 miles before my clutch cable snapped at the end underneath the car. I figured it was because I had never replaced it and some threads on the cable were messed up already. Went and got a "stock" replacement. Drove 1.2 miles and that one turned into this picture (broke inside the covering, near the middle). Did some searching on here and found lots of recommendations to go with the Maximum Motorsports clutch cable, firewall adjuster, and quadrant. Before it was all stock with no FWA.

Now that I will be installing the quality kit, my big question is why might this have happened to a brand new cable and how can I make sure it doesn't happen again? Is that something that the MM kit should fix or do I need to do anything else?

Ok so cause could be routing or quality or both. I might have bolted that bracket to the wrong hole or at the wrong angle. but I definitely routed it above and in front of the motor mount then back underneath. Anybody happen to have a picture or two of the routing?

Also, this might be a dumb question, but how do you tell when / how much to adjust the firewall adjuster? Is it just preference on where you want the clutch to engage based on test drives?