Looking for jobs related to evolution of metabolic function regulation. Please post if known

Does the present definition of a scientist involve writing research grants and managing projects? Are there alternatives to such an approach? Doesn't exploratory science lose because of such an approach, as grants are most available only for hot research topics?

I'm very confused. What are the possible postdoc options for a PhD in metabolic network reconstruction? Do I need to restrict myself to metabolic network reconstruction? What are the chances of expanding my boundaries? Will a Principal Investigator (PI) choose me for new unrelated topics? Is applying for open positions a good option or write a research proposal and approach for PIs directly, irrespective of position?