Good ideas.
I think also that Minister of Finance and Governor could be 2 different positions. The Governor has control over the central bank org, and tends to be a more long term position of someone greatly trusted in the country. The Finance Minister usually changes each term and can sometimes be a new citizen. There should also be more functions in the economy module but this is well covered by the bring back something like version 2 campaign.
Minister for Immigration would be a good position, and they could also be voted the power to either have sole approval or to call for a congress vote on each citizenship request.
Secretary General should be a country position, like it is in parties and alliances. The person who keeps records, moderates any external forums, and calls for votes on things outside the limits of mechanics. They could also have the power to mass message the whole congress with one click.