[gerbilly]

>What is the appropriate age to begin using profanity?

Any age, just don't let your parents hear you. It was a hilarious and harmless way to blow off steam when we were in kidergarten to swear like truckers.

> If I'm out at a restaurant with my "brogrammer" friends, and a mom with kids is at the next table, is swearing inconsiderate, or OK?

It's inconsiderate.