So, how do you experience life and practice in such a Christian society?
Just like everyone else - one day at a time.
Do you feel outcast,
Not in the least. I pull my pants on one leg at a time, just like everyone else.
are you prepared / happy to speak up about your religion?
If somebody asks, yes.
Do you feel culturally disconnected, alien, out of the mainline, a bit of a loner as far as Buddhism is concerned?
If you mean my Buddhism being a factor in feelings of disconnection, etc., nope. I live in a society pretty much devoid of culture. There's not much to feel disconnected from.
Are you sometimes tempted to simply go with the flow and do as others do?
Nah, I've never been one for that. I do my own thing and leave others to do their's. As far as Buddhist society is concerned, I'm not one to toe the line either. I'm not what you'd call a typical Buddhist. My life and my karma is my own and how I deal with both is not always informed by what others think or do.
In my experience, Christians are generally more interested in learning about my beliefs instead of trying to convert me. Most people, Christian or otherwise, don't give a damn about your beliefs. If they do try to do that, it takes me about 5 minutes, explaining some of my personal history, and any attempt to evangelize usually goes down in flames. I've been there, done that, have a t-shirt to prove it along with a family utterly destroyed. I'm the LAST person a Christian wants to preach the gospel to.
For the most part, my life is pretty much the same as anyone else's. I don't hide my beliefs, but I don't make a big deal of it either. I find people, including Buddhists, who wear their beliefs on their shirt-sleeve to be boring as hell. I see it as shallow and inconsequential. "Oh, you're a Buddhist? Gee that's nice! Now, how about them Broncos?"
I also think that any feelings of disconnection or alienation we may have are more our own fault rather than the result of some external condition.