Please read for an updated status on RailsCasts:
Learn more or hide this
GitHub User: nrdobie
You don't need to change the import at the bottom. On line #63 of the foundation_and_overrides.scss file there is a list of all the modules and you can just set the one you don't want to false and they'll be excluded.
Respond.js will make Foundation work. I would suggest adding it right after your stylesheets to prevent flash.
Also for IE7 support you will need the box-sizing polyfill found here https://github.com/Schepp/box-sizing-polyfill