the inherent flaw in this is that if only one person had control over furniture and such people would complain about not having any say in what the house looks like. on the flip side if everyone can move or place furniture and such at their leisure it will spark problems with people trolling or removing or moving items out of spite or anger or without permission.
really it's best if people not share plots of land
It could turn into a place where people just trade furniture for free- like crowns furniture. Additionally, others could pick up gear sets on mannequins ether without permission or if it was something valuable like commander robes.
I think it's perfectly reasonable to let people become closer in the traditional way of questing, visiting houses and standing around the commons. We don't need an overly complicated and flawed system for the sake of socialization in a game that's social by nature.