If I mix rum, gin, vodka and scotch whisky, put it in a water bottle, and leave it for a month will it be safe to drink?

Gin, vodka, rum and whisky are all distilled spirits, so you'd be essentially mixing up essentially four versions of same thing and get to a different version of the same thing. Individually the alcohol content in these spirits more than high enough to prevent microorganisms from growing when stored for years in a closed container, including the the plastic bottles they're sometimes sold in. When mixed together this will remain true and there's nothing about any normal water bottle that would change this.