I'm not OP, but that would be strange -- they offer a search API and a video player API. It would mean that they offer all the tools for you to build an alternative interface and then not let you do that?
True all these tools together can be used for building an alternative interface, but the company actually have APIs so that external services are able to integrate into their ecosystem. All the APIs are meant to be used together but each service can choose the API they see fit.
Hopefully they don't nuke my account.
No scraping or mean stuff, it's all above board and using Google's APIs.