there was no way my mom, sis and I were going to fit in. Just too way different backgrounds/expectations. If I had known, I would not have gone.
I don't agree with that. I live in an area where a large part of the population is fundamentalist protestant and socially conservative. I was a Catholic around people who believed all drinking of alcohol was bad, would not play cards, wouldn't go to movies, and didn't let their kids go to dances. Many of the people I hung around with were like this. They've loosened up a bit in recent years, but even years ago, there was no reason that someone who wasn't that conservative couldn't attend a party and enjoy themselves. They have their beliefs and you have yours. If anyone gets pushy on the subject of religion, where you know neither side will change, you don't allow yourself to be dragged into an argument. If the Bible comes out, and you don't share the beliefs, you sit quietly and respectfully, just as you would at a wedding or funeral in a church that is different from your own.
As far as this specific shower goes, yeah, the Bible reading is strange. As far as the rest of it, the too casual dress and nightgown gift, these missteps happen in everyone's life. There are regional differences in these kinds of events. In my area people wouldn't wear shorts, but I'll bet there are places in Florida or southern California where it is done. In my area lingerie isn't give at bridal showers that are for relatives. Usually lingerie is given at showers that are limited to the bride's close friends. You found out that they do things differently than you were used to, so in the future if there are events, you'll have a better idea what to do, and you'll feel more comfortable. There's no reason to avoid people because of something like this. By the way, the lingerie you gave can be pretty pricey, you were very generous. I'll bet the bride ended up using it.