json,schema.org,review,linked-data,json-ld
Apart from the comment and two comma errors this is valid JSON-LD. I wouldn't expect this to show up as a rich snippet though. The page you referenced lists the entitz types for which reviews are supported: "We support reviews and ratings for a wide range of schema.org types, including...
The semantic web / linked data lives of the re-use of existing vocabularies, so if you only need a sub-set of existing vocabularies, it's best to not re-invent any new schema, but just to use parts from existing ones. Your data will then even be useful without any reasoning. Also,...
From the perspectives of Schema.org, JSON-LD, and the possibly extracted RDF, it should not matter. The data is the same, no matter from where in the document it got extracted. From the perspective of HTML5: If it’s data about your page (or what this page is about), you could place...