Ukraine should agree to recognize Luhansk, Donetsk and Crimea as Russian in exchange for getting back the currently occupied areas of Kherson and Zaporizhia. It should also get an agreement with several states for a military alliance: probably the Scandinavians, Baltics, Poland, Romania and Turkey. Plus EU membership. Putin gets those territories, no NATO, and gradual lifting of sanctions as both parties comply with various steps. Transnistria should go back to Moldova to prevent further Russian provocations.
Your #18... interesting points.
Although unfortunate, that is probably the best deal that can be achieved. And the sadness is that Russia could have annexed Donetsk and Luhansk without firing a shot and with a response no greater than a strongly worded letter, but Putin had to be greedy and try to get more.