1) Yes, as long as the quotes are supporting an argument and aren't just being pasted for no reason.
2) Yes, as long as you don't demand people pray with you. Also, I was pretty sure that prayer took place in one's own mind, so I fail to see how we could stop you from doing that anyway.
3) Yes, as long as you realise that quotes from people who aren't actual authorities on the subjects they are talking about won't be taken seriously. See: Appeal to Authority.
2) Yes, as long as you don't demand people pray with you. Also, I was pretty sure that prayer took place in one's own mind, so I fail to see how we could stop you from doing that anyway.
3) Yes, as long as you realise that quotes from people who aren't actual authorities on the subjects they are talking about won't be taken seriously. See: Appeal to Authority.