I was raised in the AG, so a little different situation, but not as different as you might think. We didn't call our rules "standards", but it's about the same thing. Oh, the
list of rules/standards was different, but a lot of ours weren't found in the Bible, just like a lot of yours.
They changed over the years: when I was a kid, there was absolutely no problem with Halloween, but we couldn't play pool. Now, it's just the opposite -- in a most AG churches, anyway. (That's another similarity we have with you guys: the rules vary a lot from church to church, and even from family to family.

)
Anyway, in my case, I "left standards", so to speak, gradually. (Slippery slope, you say?

) Never really followed the no-drinking rule, from the time I reached drinking age. Just didn't buy it, since it wasn't "Bible". Didn't drop the tithing rule until I was in my forties.
How was I treated? Not too badly, really. Even today, I just get occasional "advice" from Mom about it

, but otherwise, no problem.