This stuff you mention is all well and good until you can't find people to do it with or people who can't be bothered to help.

Try doing any of those FF11 door mechanics now and you will find it very hard to get people to help you.

I would like to see these kind of things in instances though when you already have a party formed, didn't Yoshi-p suggest that all dungeons would be converted to instanced area's anyway which means its unlikely to happen "open world"