lol
no
I don't think it's a bad idea at all, but at the same time I'm not sure I'd use it... I'm not IC all the time and having to toggle it off and on depending on my mood and the chat channel(s) I'm using at the moment would be too much work. If I did have it on, however, I would prefer it to be a filter of it's own as opposed to being part of the profanity filter. I have no issue with there being profanity in the game, both when IC and when OOC, and I always have my profanity filter off.
I know what Synapse is saying and KanoR's example is pretty close to reality. It would annoy me to see it in LE posts but to be honest you can't prevent those who aren't into the RP side of things as much as other from turning up to events and there will always be those who'll circumvent the filter, so there's no point getting annoyed. All I do, if I see someone adding chat like that in area is ignore what they say. I don't respond to them if they're trying to get attention or are trying to be clever or are just being OOC etc... However, I'll react to a LE character if that character responds to them. I guess it depends on the situation.
What I'd really like to see is an intelligent spam filter... well I can dream...