Thank you for the questions.
1. Currently you would need to do something custom to accomplish this, although it should not be difficult to achieve. The validation we use in Studio is included in the standalone library called apicurio-data-models found here:
https://github.com/Apicurio/apicurio-data-models I would be happy to point you in the right direction on this. But we don't have a standalone tool that can do this for you already.
2. Apicurio Studio and Apicurio Registry both have ReDoc integrated. You could use Apicurio Registry *as* your centralized documentation server, although it's meant as more of an internal catalog rather than an external facing documentation server. So if you're looking for the latter (e.g. some sort of API Portal) we don't have a solution for that.