How funny. You were posting as I was editing my previous comment. Oops.
I'll respond to some of your points, not with the goal of "winning" or pushing you back into a church, but just to explain where I'm coming from now.
First >When we agree the ancient Hebrews were wrong about pretty much everything,
The ancient Hebrews were wrong to find ritual rape and prostitution wrong? I don't find that it does contradict all modern values. In the context of their time and place, many of the laws of the Hebrews limited sexual and economic exploitation, as well as violence. Intent and understanding context are as integral a part of reading as the words on the page. The direction they were heading is at least as important as the position they were holding, so to speak.
>But the Bible is the only basis for any of the central tenets of Christianity,
Despite some evangelical theology, the Bible is not and has not been the sole basis for Christianity in general, or Christianity couldn't have produced it in the first place. Jesus is the basis for Christianity. The Bible is part of the church's tradition that tells us about Jesus. It also, like any other authority or source of information on earth, isn't pure decontextualized Truth.
There are plenty of alternatives besides "The Bible is a divinely dictated instruction book" and "vague fortune cookie approach to love."
There are also alternatives to "The Fall literally as described in Genesis" and "no such thing as sin." I'm reading The Work of Love: Creation as Kenosis now, and it touches on that question among others.
It also sounds like your church's primary understanding of the crucifixion was penal substitutionary atonement, which is not the only theological option. There's Christus victor, for example, which seems to have been at least as prominent in the early Church and Orthodoxy.
Hope that's somewhat coherent. Back to making dinner...