@qwerty yes, after running ./nodebb stop, NodeBB should not be running.
What did you try? Does it work when running with ./nodebb dev?
templates.js is a hybrid client/server templating engine (or rather, it is platform agnostic, as it is just plain javascript). It runs on server-side when you cold-load a page, and runs in the browser when navigating between pages.
@psychobunny can provide more details upon request