Are there plans to integrate voice chat through the chat service?

No voice chat, but since you can reply to chats during live chat that is something like voice reply as well.

Of that I'm not sure, honestly I use Discord on the side and find it to be the perfect companion. Because Discord at this stage is so rich in features and offerings, it will be hard to beat. Where the Restream chat comes in VERY handy is the chat relay between compatible services (not all services offer chat through restream or relay). This feature is VERY hard to find anywhere and Restream's works really well. So for now, checkout Discord :) if you haven't used it, you'll fall in love quickly, at least in the meantime until Restream brings out such a feature, although honestly I don't see it happening, because of Discord and some other platforms like Teamspeak and Ventrilo etc. If you need further assistance please let me know! :)