1. Each cable has a bend radius recommended by the supplier. If this bend radius is exceeded (too small) then it is very unlikely that the cabling will function properly electrically, especially for high speed communications. Cross-talk, dropped packets, etc. If anything the supplier is off the hook for meeting their spec since it wasn't installed correctly.
2. The plastic insulation will take this for a while but two things happen to polymers with a constant stress on them.
2.a They suffer stress relaxation via creep. The long linked molecules will reach a new alignment over time. They will no longer be in their plastic range and settle in a new configuration. This could result in more crosstalk or even a complete insulation failure as a function of time.
2.b Flexible plastics typically slowly lose plasticity over time due to the breakdown of the plasticizer that made them flexible. (That nice new cable smell) Most cables have PVC made flexible due to these additives. If this box is warm due to the heat from the drive and pi, then it's entirely likely that the cable could further degrade under the constant strain and creep and fail. Causing not only thinning but brittle breaking of the jacket. It doesn't have to be visible breaking for it to stop working electrically.
Basically you can't trust your wire anymore. It could work forever. It could fail randomly. It could just cause communication errors that are hard to trace.
As for the box, they just used too much plastic and pushed the thing through the machine too fast without cooling. But then again, I am not an ultra expert on injection molding. It's an art. My recommendation would be "Have a sit down with your molder, these faults do not need to be."
