First level control: Is there a mandatory or recommended percentage of each partner’s budget that should be allocated to First-Level Control? Should these costs be included under external expertise and services and linked to a specific deliverable?

There is no mandatory recommended budget or flat rate. It is, however, recommended to calculate with market prices for all partners in a decentralised system, as they are depending on an external controller. These costs must be  indicated in the budget under the external expertise and services budget line. It is not necessary to allocate the national control to a  specific deliverable or to take it up to the work plan of your project