There’s Christians living in Gaza for centuries. They have churches. Hamas does not harm them. That “pure Muslim state” isn’t being enforced on a group Hamas could easily oppress. Not sure where you’re getting that from.
Recently there were Christians in Gaza in a Church which were sniped down. And the snipers weren’t Hamas. They were IDF.
Hamas has always maintained that they have a problem with Zionism not with Judaism. From their 2017 charter:
Hamas affirms that its conflict is with the Zionist project not with the Jews because of their religion. Hamas does not wage a struggle against the Jews because they are Jewish but wages a struggle against the Zionists who occupy Palestine. Yet, it is the Zionists who constantly identify Judaism and the Jews with their own colonial project and illegal entity.
As for the second part, israel is the party which refuses to come to any agreement. The israeli cabinet very openly states that they will never recognize a Palestinian state
Hamas has already said they are open to negotiations in their latest ceasefire deal.