"Have they agreed to the two-state solution?" Yes, with final details to be determined in negotiations.
"What gives them any more right to the west bank than the Jews?" They were living there first. And the UN resolution that created Israel and called for a Palestinian state. That they lost a war to Israel means their land is currently occupied, but is still their land.
"Was it the PA or the Israelis who took the west bank when they were attacked?" Israel occupies the entire land.