The alternative (I don't think Jordan would agree either, but they could be prodded) would be a unilateral separation, creating a state in Gaza and part of the West Bank. Terrorists expelled, peaceful palestinians stay where they are, but are citizens of the new "palestine", rather than Jordan, but not Israel.
You're 100% correct. I don't know the history of it, but they probably thought that if they negotiated in good faith, got an initial agreement with Egypt, that would be followed by good faith efforts to solve the refugee problem. My sense, though, is that many of the people in the West Bank, and perhaps Gaza, aren't "refugees," but Arabs from other Arab nations attracted by Israel's economy. "The Palestinian People" is something of a myth.