I am confused by your statement that you "opted out of the judgment business some years ago." While Jesus certainly admonishes us not to judge and even warns that we will be surprised by God's final judgments (see Matthew 25:31-46 especially), this does not supersede the fact that God judges. So you can certainly opt out of judging, but as a Christian you cannot opt out of worshipping a God who judges and who will judge.
And I must warn you about your alleged "disqualification" about being labeled a fundamentalist. The best definition of "fundamentalist" I have heard is "someone to the right of me." So watch out whom you shake hands with.
Your summary of the ethic of the Christian life is wise and commendable, and I can only hope to live up to your standard. But when you say "preach the gospel," doesn't that include some intellectual content about who Jesus Christ is and our relationship to him now and in the future? And doesn't that gospel hold out the hope for people being "saved," both from our sins and, more importantly, from our alienation from God? What I am getting at is that I do not see how we can sidestep this uncomfortable fact that the flip side of the "good news of Jesus Christ" is bad news for those who reject him. Yes, Jews and Buddhists and Muslims and Hindus and atheists don't like Christianity's exclusiveness, and there is much about the last things that Christians should be rightly agnostic about, but the gospel will not allow us to be content with a "live and let live" ethic.
Your comments about the there not being "much room for triumphalism in the Christian life if we take seriously the Christian doctrine that we are sinners saved by grace" is absolutely right. But Scripture itself is permeated with triumphalist language. The difference between Scripture and what you are condemning is that the Bible does not triumph over people but over evil, even the devil. We fight a spiritual war, and our head warrior is a lamb whose victory came through sacrificing his life without resistance. So the triumph of the heavenly banquet is not that we "won," but that we stand with all that is good, right, and worthwhile, and we are with the one who is love.
My point regarding the "Left Behind" books is that its triumphalism has much to do with the simple fact that God is vindicated in the last act of history. You can write a much less sensationalistic book about the last things and still be labeled triumphalist by simply saying Jesus is the one standing at the end. My criticism of the "Left Behind" books is not that they are triumphalist, but that they are simplistically so. Their paradigm for how God works is so American, so tribal, so superficial that I can't help imagining God wincing.
See you at the rapture.
Michael G. Maudlin