On the word "balance", see the GP, Section 1: ...BALANCING SUSTAINABLE DEVELOPMENT, COMPETITIVENESS AND SECURITY OF SUPPLY.

Key sentence (p.4):

Sustainable, competitive and secure energy is one of the basic pillars of our daily life.

I don't think the phrasing of Q.9 invites us to rate these principles, let alone reduce one of them to zero -- and I doubt many people will understand it in that way. Balance implies equilibrium implies equal weight. If they meant what you thought, I think they'd have said "mix".