Stemmed from the thread disappointed in how stages don't have the floor attribute and thus cannot actually hold chairs and musical instruments on them (in case we wanted to make a string quartet in the FC), I suggest we look into the possibility of going farther than just instruments on the stage.
Specifically, what we actually expect from a stage: stage plays.
While ideally the stage will have an actual "floor" attribute, not just a tabletop attribute, so anything could be placed on them, be it a couch and table for a talk-show, or a single mike for a comedian, I believe players would also be delighted to have an array of stage-specific "props" resembling the light drawing styles of Khloe Aliapoh in her journal, to stage out their own "plays", or just to set up a still scene via creative placement of the props, and theatrical lighting. At least two dozen props, from trees to castles to goobbues, should be initially designed to allow for liberal creativity in scenes, with more to come steadily. A hand-operated, colour tinted beam light would also be a fun addition for players to play around with. And a moving stage curtain would just be pure fun.
If the props are specifically limited to the area of the stage, there is also a possibility for more advanced customization when staging a play. Semi-programmable machinery (via simple coding resembling player macros) can move props right, left, front, back on the stage; or to move them up and down via strings and platforms as the play necessitates. The non-player operated theatrical lights could also be set to auto-follow specific "props" as characters, during select sequences.
Speaking of Theatrical Lighting, I suggest looking into additional supportive furniture akin in purpose to the current wall partitions, so not really furniture in themselves but more like architectural accessories, to facilitate better placement of furniture. Examples can include "Scaffolding", "Ceiling Hooks" etc. to allow for vertical creativity beyond just horizontal creativity. These combined with a stage with floor attribute would allow players to set up interesting combinations, such as performance stages complete with backdrops. This is also a solution to address the unsatisfied passion of players to be more creative in their furniture placement, evident in the use of "air snapping" to accomplish layouts not otherwise possible. But with items such as "Scaffolding" and "Ceiling Hooks", such layouts may be accomplished without having to resort to tedious air snapping.
Thus is my proposal for a stage-play feature in player housing. This "game within a game" will add to FFXIV, and architectural accessories will improve house furnishing freedom and the aforementioned stage plays.