Usualy yes, But it might help if you can get your and in there with a paper towel and see if you can pop it out.
Is he fixed? 6 months is around the time when hormons start kick in. He might feel that he has to mark his turf.
I can't answer this one, because my dogs do this. I don't know why! Cheecho (2) has grow out of his for the most part, but if he is barking at the door, and some one goes to pick him up, he will pee. Bria (7 months) can't be held or touched by strangers with out peeing, or when my dad gets home she gets so happy to see him she rolls around peeing on herself >.<