Hey thanks for your question. The original L&F is currently under Creative Commons license CC-BY 4.0, however S&S is under a CC-BY-SA 4.0.
This means that if you use anything from S&S that was originally in L&F, you need to credit John Harper. If you use anything that wasn't, and was instead written by me, you have to both credit me and also share your hack under the same CC-BY-SA 4.0 license.
Both L&F and S&S allow derivative works and commercial use in their respective licenses. That means you can feel free to hack away, and then distribute your hack however you please (as long as the hack is shared under the CC-BY-SA 4.0 license if you've used text from S&S).
Essentially, if you copy/paste anything I've written that's fine, but you have to let others do the same to anything you write.
More info on the CC-BY-SA 4.0 license can be found here: https://creativecommons.org/licenses/by-sa/4.0/