You might also want to bookmark Zclassic on Reddit, as it's still more active than BTCP subreddit
https://www.reddit.com/r/ZClassic/Any update about the date of fork? When will it happen? What are the exchanges can support it?
Propably end of February/early March. No info about exchanges yet, but they are fundraising to get in to major ones and that is the main reason fork is set to happen 4 weeks from announcement.
What is the total/max supply of the BTCP coins?
Give or take 20 million after fork. Bitcoins in circulation + Zclassics in circulation. Max supply I think around 22-23 million. It was thought to be 21 million first, but back then circulating supply of Zclassic was counted wrongly (around 1.8 mil.).