Three things that would make housing more awesome (in my completely biased opinion):
1: Increase furnishing limit. Ideally, increase the total limit for all furnishings substantially. I haven't started furnishing my Grand Psijic Villa and I currently have no plans to; given how enormous it is I know there is no way I will be able to fully furnish it with the current cap. For reference, my fully furnished Pariah's Pinnacle is currently at 673/700 and it is only a fraction of the size of the Grand Psijic Villa. Additionally, it would be nice to increase the special furnishing limit. Even though I have 27 generic slots free, I am unable to place any more of my camel mounts since there are only 10 slots available for mounts/assistants
2: Make housing giftable. At the current excange rate on TCE being 225:1, players would save about 1mill gold buying an unfurnished notable home via gold for crowns as opposed to paying gold directly to the crown store. Players would get a discount this way, and ZOS gets to sell more crowns instead of just having homes purchased by gold be an infrequent gold sink. Seems like a win-win to me.
3: Create additional areas for existing houses. Almost like an in-house dlc that unlocks more area similar to what the tablets do for the new elswyr house. For players that are content with having one well furnished house rather than several, it would be really cool if you could continue upgrading them rather than furnishing it once and being done with it. For example, creating a new lookout area/structure at the top of the waterfall in pariah's pinnacle would be pretty awesome.