Just a few enchancements/changes for chunk claiming, since the current chunk claim systems is really restricted. Add some flags from that of WorldGuard. Flags like the build, use, vehicle-place, chest-access, vehicle-destroy, and the greeting/farewell message flags that we can turn on and off in certain chunks wouldn't hurt. Like, if the chunk is claimed say, under a friend's list, then those on the friend list has complete access to the selected claim, and if their not, you can turn on/off WorldGuard flags for people who aren't on it. This would make things like a rail line possible without the fear of someone griefing it or perhaps a town/public place where you'd need to give people access to doors, buttons, etc. (Starbucks?) but don't want them griefing/setting the place on fire.
Lemme guess, business ventures ehh? Anyways, useful idea although the majority of the players aren't the most inclined to share what they have made. The only thing is that the system has to be made to be as easy as cake. It's hard to explain complicated things over chat if ya know what I mean. It's not like anyone ever reads the wiki.
From what I've seen, players love to show what they've made, they just don't like giving other players they don't trust access to their machinery in full (things like breaking/placing blocks). A main reason why few tends to do public projects is because of the other few that'll just exploit it and grief. I'm sure players would want to do a project like spawn where you can open/use certain things without breaking/placing blocks (adventure map/towny style). Who knows, maybe we'd have more public areas around the server instead of just everyone just building a base where only their trusted friends can see it. As far as the user-friendly part of it goes, if he just takes the basic system from WorldGuard, and modifies it a bit, it'd be as simple as selecting an already claimed area and running a command like [typed]/flag use true[/typed] It doesn't need to be on the front of the welcome page on how this more in-depth system works, as it won't be required for the average joe who just needs to protect their land.
I totally understand. Don't take my opinion as a rebuke towards your suggestion. I'm just merely stating my opinion on implementation details because the rationale for this was already well stated enough by you. Besides, it's up to SK to decide how he wants to implement it, because I'm sure you, me, and SK would all want something easy to use as well.