I'm sure you'll get lots of suggestions. Here are several I'd make sure I'd have checked:
- The number of times the engine was reved over red line
- The cam shaft angle variations at idle - they should be rock steady
- The cam shaft angles themselves. Spec is +/- 4 and slightly out of spec is OK. If too far out of spec, there could be problems with the variocams and chain rails
- Debris in the oil filter, especially metal