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If the debt ceiling isn't raised, simply prioritize what the country's money is going to be spent on."
1. That could be a form of default. Not on the U.S. debt, but on its contracts.
2. Cash flows are lumpy - that's part of why we have government debt. Even reducing all non-debt payments to zero, the U.S. Treasury will have to default at some point before mid-November. There simply isn't enough money in the U.S. Treasury's account at the Federal Reserve to keep its cheques from bouncing.