Sometimes. Never to children, strangers, old people, or family, and only in appropriate settings. Sometimes when I get very angry I do, but not with people. I actually find it more effective in scaring people I am pissed at by mixing weird insults with swears. Usually confuses them XD
Not so much, but on occasion - usually when I'm startled or I smash my toes against the corner of something for the billionth time, and that's mild swearing at best. I don't say the F-word and I don't profane the lord (i think that's what it's described - "jesus!" this and "god..." that). Most of my swears consist "cheese and crackers!" and "criminy!"
I've been living with and around ski coaches for my entire life. So, fuck yes. It's not even something I think about anymore, but I stop when I'm around younger kids or other people who would find it disrespectful or agitating.