Furniture maintenance is unrealistic and tedious. A person will generally replace furniture, not repair it. Replacing an item with the same item isn't exciting. Alternative thoughts:

1) Add a "tier" rating to housing objects. Reduce the housing bonus of T1 furniture within a T2 house, and even further in a T3 house. You should replace (not add to) your furniture as you progress. This will add to the impact of "garbage collection", which is also needed.

2) Reupholstering: Allow crafters (probably tailors or painters) to update (and even customize) an existing furniture item. Increase the housing bonus accordingly.

I have some concerns about the Maintenance feature, mostly around functioning property that becomes abandoned with laws that prevent interaction for non-citizens or owners.

There's a very large part of the playerbase that prefers the 'burst' playstyle and after a week or two they poof, often leaving behind a very nice settlement, trading hub, housing, roads and other infrastructure. And laws that try to preserve their efforts infinitely by preventing immigration and takeover.

Once Maintenance goes into effect, will these abandoned claims go into disrepair? Will their laws also degrade? This could allow other active players to at least repair objects and help to ensure that production facilities continue to function. Is there a plan for how to work with the abandoned mechanic?

Without a plan for abandoned property, longer term servers will end up a polluted wasteland regardless of active player efforts to mitigate pollution.

Only should degrade if used. If not used it shouldn't. Other games also make it so that furniture doesn't degrade if on a "paid" land or deed, but if off it, slowly degrades on claimed spots, if unclaimed it degrades faster.

Need to be careful on features like this. It can become micro-managing and make people less happy in the game.

Furniture should have HP or durability ONLY if it has function with purpose. If coupled with, say, the feasting feature for cultural and calorie-banking purposes, then by all means said table and chair could act as the multiplier and needs to be cleaned/fixed once its use (should be pretty high, btw) has come and gone?

Also, this would be great for making obsolete furniture fall into obsolescence and be turned into garbage for recycling and reprocessing.

This feature should have a way to be turned off in the server management. Similar to how food preferences can be turned off.

Additionally, the feature should use the contract interface and require skill labor.

Downvote. I think this would make a cool mod but should absolutely not live in the base game. Too hardcore and tedious

That sounds a little hardcore. I don't even have to repair my furniture in real life.

If the goal was to give Carpenters more work to do, I'd almost rather just have a Burglar specialization break into houses and steal furniture. At least the economy would be getting injected with new* available goods that way.