You can query the Graph api directly by working with the GraphApi super-interface. You can also get a facebookTemplate.getRestTemplate() and invoke at that low-level. Each request is signed with the access token for you. You don't have to worry about that.
I would consider forking spring-social-facebook on github, designing support for the functionality you need into the Facebook API binding, and submitting a pull request back. Check out the wiki for the root Spring Social project for Github contribution guidelines.
Core Spring Development Team