if the front mount broke sounds like he didn't fill it in with balsa as required in the instructions.
as for the twisting out, sounds like a weak elevator joiner like i had, but mine was still perfect in KE, just 3% mix on ailerons, but it changes in different wind conditions anyway.
thinks to check.. did he line up the engine mount with the little hole in the firewall, did he get the firewall the right way round to start with? ( puts the hole on the right side )
Sounds like he got something really wrong.