Lol, 44 pages of arguing and then he's like, "uh, hey guys, this debate is kinda... irrelevant." Glad I didn't read it all (just dunk and cev and a couple of others' comments who mostly responded to everyone else anyway).
Still, though, would be nice to see some sort of ability to have aboveground functioning towns, which is more or less an impossibility in vanilla mc. If you just got rid of those damned nametags (hate those suckers, never understood why there wasn't a common mod for getting rid of them in pvp servers; I mean, I know it has to do w/ how it's handled, the only way the client displays a player is if the server sends a a package identifying that player which contains the name, but its hardly rocket science to figure out how to get around this and I've seen a couple of small mods that did it then just kinda faded away) then you could AT LEAST have viable underground settlements, which is currently made useless by nametag hunters on any good sized pvp server, but it'd be lovely to see some of those fantastic structures and towns constructed somewhere other than a creative server and, you know, fought over.
Personally I always thought that a mod that added real difficulty to mining and construction would fix a lot of it - mining a cubic meter of stone or dirt takes at least minutes, you can't load your inventory up with it but have to (slowly) carry one at a time from place to place (they don't turn into items in other words) or load them in minecarts (would actually give minecarts a function, in construction projects), and ofc it would then take forever to get through a good wall. Perhaps even make it harder to mine blocks back out again after placement with the addition of some substance such as mortar which doubles their difficulty or somesuch. You could even Throw in lighter materials for unfortified buildings like real wooden planks that could be laid from support post to support post creating an enclosure out of two dimensional thin walls that were as easy to break thru as current mc materials but could be stacked to some degree in inventory.
Ofc such a taste of realism (well, realism lite, because carrying a single cubic meter of stone over your head is still pretty fantastic) would be sacrilege to most MC players. What might actually work is something like the system originally suggested with the home stones or w/e, and the addition of -limited- siege equipment. So you can protect just like you can in factions and other plugins (though a larger area would be nice to encourage big farms and plantations) but they can get through without the whole water cannon thing (which would necessarily be removed). Basically you would create a catapault, ballista, or battering ram using assorted materials (wood, metal, and most importantly glues). These engines would have two very important characteristics - they would degrade QUICKLY when moving over unpaved terrain (dirt, natural stone, etcetera), breaking down in as little as a hundred blocks (something which could be adjusted for balance), and they would have a cooldown time between construction and first use. This would be explained by the drying time of the glue (this idea wholly nicked from a little mmo I used to play and love called haven and hearth, but it worked damn well there) or whatever else you wish. Drying time could be anything really, but twelve hours would work best. Once the thing dries you can fire on the wall, and the missile's hit would have the effect of a chisel, chopping off one or more layers of block (depends on the material of the missile and of the block being hit ofc) at a time whilst making a terrible racket that travels long distances and with considerable inaccuracy so that it takes a while to batter through any two block segment that you can fit your raiders in.
Basic thrust of this idea is obvious ofc. If you want to raid a town (that didn't screw up and leave a route for you to parkour over their walls, such as nearby trees or something) you've gotta place your siege engine more or less WITHIN SIGHT, or at least within easy patrolling distance of them, which is realistic enough considering that until the construction of metal cannonry which made it impossible to assemble onsite this was how siege equipment was used, to keep it from slowing the army and arriving useless from the wear and tear of the march. Then you've got to wait half a day, giving them plenty of time, if they're active and alert, to find your ram or catapault and destroy it - or better yet break it down for materials and set it up nice and pretty on their wall as a sort of roundabout 'fu' to the raiders when they log on the next day. If they somehow miss it and they're online when the raid commences they're sure as hell gonna hear it, and be able to at least attempt a sortie. On top of all of that a wall chewed and chipped to bits by a catapault is going to look pretty friggin' awesome, which is a fringe benefit, but the whole town isn't gonna be wrecked and griefed because they're only going to be able to move the sucker around and do so much damage before it breaks down and requires glue and drying time to fix up again.
I think it'd work pretty well. The siege engines would probably be a pain to program, but then what good mechanic isn't? It'd allow raiding, though, whilst still allowing even relatively small teams to protect their home if they bother to ass themselves just enough to look around the walls for bits of siege machinery hanging out and trying to look innocent every so often, and it'd make griefing (tearing down people's bases or burying them in cobble or w/e just to be an ass, without benefit to oneself) too much trouble to be worth it to the sorts that do it. The siege engines would also make MUCH better defensive weapons than offensive if you allowed them also to be loaded with stacks or rocks, which ofc would do no damage to blocks but would act like a flight of super high-damage arrows against players and siege equipment outside the walls, and ofc they wouldn't break down if they were just sitting on your walls and not being moved.