Q 2. Can I create one single COFUND budget code for the whole department

In principle yes. However, as the COFUND budget code should have the same parameters as the CERN one out of which the 67% are paid (same PPA, same responsible, etc.), it is unlikely to happen. This is why a budget code per group has been requested by default. This COFUND Budget code should be linked to project EU8-MARCO5.