Peter:

Well, I guess my concern is that for a wedding, I don't get 2 or 3 takes. I get 1 take, and I need to make sure I don't screw it up because I'm using a filter. If I was just shooting a creative shot, that'd be fine, but I'm thinking about outdoor ceremony use and outdoor reception use. In your opinion, is it 'safe' to leave the circular polarizer on while you're shooting 'on the fly'?

Also, not sure what you mean by 'lighting arrangements for nightclubs'. What kinds of shots are these (dance floor shots?)?