Awesome. I didn't know. I'm going to try to get as far as I can using my rudimentary knowledge of how an emulator is supposed to behave and a reference to opcodes and such.
Sure. If it's a question that might be relevant to Octo (especially things to do with quirks modes or programming techniques or ergonomics) you can ask a question on the Octo Github page or mailing list.
Despite the widespread cursory interest in CHIP-8, as exemplified in all the VM implementations in this comment thread alone, there isn't currently any sort of centralized community for it. The users and developers of Octo are open to furnishing that to the extent they're able.
When you say to just ask, do you mean here on hn?