It would be interesting if there was some sort of community building project...

[Shougun]

No thanks. I hate player created structures, towns, etc.. Often times they make absolutely no sense, garish, and ruin my immersion. At least housing plots are contained to the specific plot.

I think that is why having it localized to a FC would do well. I know OP was thinking more big picture, and maybe I guess it could be 'alliance FC' content, but I think taking many of the core desires yet going a bit smaller scale (not Ishgard lol) and perhaps not 'as' free form (hence reference to Dark Cloud, although personalization capabilities would still be very important) would still maintain a lot of the desires end result wise but also add a lot of content that I think a FC needs (FC centric content, things to do with your FC). The group, industrial, focused brother variant of Sanctuaries.