How's this for a warfare mechanic?

So I've been thinking about making a new pvp plugin, specifically to designed to encourage creative castle and trap building. Honestly I think this is the best part of the game and I want create some balanced competition without people just being able to grief anything sight.

My two main ideas are to use economic incentives to encourage pvp or p v castle combat and to allow players to protect blocks in a way that does not make them absolutely indestructible.

1) There are no private chests in the normal sense. The goal of the game will be to accumulate wealth which can then be used to attempt to protect your stuff. However hoarding will also encourage other players to try to steal what you have. The only way to can protect your items will be by building an good castle.

2) Players will be able to purchase protection for blocks. Basically what this will do is make it so that a block must be destroyed more than once before it will actually disappear. So, buying 10x protection on a block of cobblestone will mean it has to be mined 10 times before it will disappear.
- Block protection will be player agnostic. Once a block is protected even the 'owner' will have to mine it multiple times to remove it. (no placing a diamond block and giving it 4000x protection to keep it safe). Also this means castles have to have real entrances, so that if it's possible for you to get in someone else has a chance of it too.

Other possible details that may have an impact on the balance of play
- Some blocks may be made indestructible. I'm thinking glass since destroying glass 10 times isn't much of a discouragement. Probably functional blocks (eg switches, buttons, redstone) too, to make make traps more robust. However the cost structure for this protection will be different. Absolute protection will be time limited, though players can choose to set up recurring payments to re-protect these blocks when time runs out.
- Protection can be purchased in bulk. The command will be something like /protectcuboid n followed by right clicking the corners of the cuboid to protect. Every block in the selected area will have its protection increased n times and the players account will be debited the sum of the protection costs for each individual block.
- Players or groups of players might be able to purchase land. Probably in 16x16 chunks. Purchasing land would make it so that only the owner or owners can build in that area, though other players can still destroy in it. Meaning you still have to buy protection for important structures.
- Owners may get some reward for people who die on their land. Maybe a cash bounty or some random portion of what the victim was wearing. So effective traps can earn you money when you're not around.
- There will be some way to convert between items and the currency used to buy block protection. Also this allows wealthy players to purchase tools and armor without mining or crafting.


I will probably add other ideas as I have them, but that's general idea. What does everyone think? Also are there any competent developers who would like to help implement a plugin like this?