If you make wood destroy-/buildable your players can build their own little shelters.
Of course Zombies are able to destroy doors and wooden planks, so it wont hold forever, but it can help a bit.
another problem that will occur is, that you will have to restart the map every week... OR refill the chests.
Because the chests near the spawnarea will be empty soon and new players will not be able to survive very long. also old players will become inactive, while having important stuff (diamond-tools, obsidianblocks) in their inventory.
Next thing is: if there are only 14 obsidian-blocks... what happens if the "obsidiancarrier" dies and the block vanishes into thin air?
But if you are restarting the world every week/month people will become annoyed because they did come a bit far but everything gets reset again. Like you play Zelda or FinalFantasy and your savegame gets deleted.
And if you refill the chests people will camp those with valuable items and farm lots of them...
Please dont see this as negative critique, I have the Idea for a similiar project. I just want to show you some problems you could run into. ;)
Oh and if you turn PvP on: Make sure you add a badword-filter/censoring-plugin.
