God finished His work by the 7th day. God does not exist in time. We don't know what God "does" in heaven. He is perfect and His work is perfect. Perfect means finished, complete. What is there 'left' for God to do. And, after the End of Times, with the new earth and the new heaven (why new heaven?), what will God do "then?"
Your anthropomorphism placeses a necessity on God to "do" something.
God finished His work in CREATION on the 7th day. That says nothing about His other work. In addition, God does indeed exist in time, He is just not subject to it. God isn't governed by time, but He sure does work within it. Does God hear our prayers today? Does He continue to work miracles on earth? Does He lead us? Does He show up for the Eucharist? How can you say God no longer does anything?