This is what happens when you send untrained people out to do a job under your license and then you don't go out to check on the job. Good thing you caught this. Make sure you check this job thoroughly and make the necessary corrections before you accept the it and put your name on it. Good luck.
I agree but if the box ko actually clamps the wire to the box as the P&S boxes do then it only needs to stapled within 12". In terms of the 2 wire per hole, I believe that is one that many inspectors turn the other way. Quite frankly I do it on a rare occasion however you are right, it may not be code.
Perhaps ? Read the instructions on a bag of "stackers"... I don't recall the exact wording but they reference 310.15(B)(2) and they have some suprising "limits" especially when it comes to #12 Romex.
I'm a real "fan" and tend to overlook the mfg limits.