If anything, the best I can see aiming for is some equivalent to cultural Judaism, where even non-believing Jews are invited to attend major ceremonies.
Hobby groups and community organizations offer a bit of this, but it seems like there's a fairly specific identity/culture gap that's not easily filled with anything else for non-Jewish atheists/agnostics.
But yeah the demographic of UU members is "High functioning non-contributors"
What's a 'big, public decision'? The Bible is very clear that there is such a thing as sexual immorality and that same-sex relationships qualify. I've heard arguments that a long series of translation errors means that certain kinds of same-sex relationships are fine, but even so, the Bible does say there is such a thing as sexual immorality. I haven't seen a church that is fine with homosexual acts that also has a coherent position on those passages of scripture.
The only coherent position that's possible is that the Bible is just a good book with a lot of good ideas, but I'm not sure how to organize a community around that principle.
Let's say I put my foot in my mouth and hurt someone's feelings and need to apologize. There is a Bible verse in which Jesus said that we need to prioritize reconciliation over religious habits. If I thought the Bible was just a pretty good list of suggestions, I could easily ignore that teaching because <insert reasonable excuse here>.
That is to say, I don't really how to remove scriptural authority and still have a clear understanding of who God is and what that means to us.
Then again, as Scot McNight makes undeniably clear in the opening chapters of The Blue Parakeet, everybody picks and chooses: it's just a matter of degree.
I think we're going to give it another try - we've since met some other members who were horrified at our experience. :-/ We'll see. If they want to drive away families with young kids, I figure they'll last another 20 years or so…