Why did hamilton believe a national debt would strengthen the united states and ensure its survival?

Hamilton believed a national bank was necessary to stabilize and improve the nation's credit, and to improve handling of the financial business of the United States government under the newly enacted Constitution.

the answer is mass marketing.

well that depends on how deep the hole is. you'd first go through te crust of the earth, then the upper mantle, then the lower mantle then the outer core, then the inner cor then you'd be stuck in the core to melt.