I like this idea

btw, I'm a levels person, I wouldn't mind working for this server.
Here are some suggestions:
it'll be a big world, with many farm/merchant towns which you can travel to and buy stuff, trade animals, etc. Then, you grow crops, etc, and there will be different weather, different tools for farming and caring for animals. You can't PK on farms, and you can lock up your farm any time though, but you can PK anywhere else though.
When you start out, you need to go to a registrer place, and then you can purchase a farm there. You'll owe money to the register place though, and you'll have to pay money weekly till you pay it off (not much, just like 5% of your income). Also, when you purchase a farm, it'll be like "Your farm is being prepared, we'll have it ready within a week" the info would be sent to the adim somehow (maybe a farm NPC?) during that time, the LAT people would set up the level (it can be generic, but a player can edit it or something then send in his version, and if approved, it'll be uploaded.) There can be like a main hub where a player can access all the farms, like if he says "Acctname's Farm" he'll be warped outside the gate of that farm level, and also, players can purchase more land (levels) to make his farm bigger (LATs would be a major part of this server, as you can tell.) You would be able to train your animals to fight, of course, and there would be tourneys every weekend or something, where the winner walks away with a trophy or some other prize...
Summary:
Player starts game, buys farm, pays off debt of farm weekly.
Main hub where all players access the farms.
Trains animals, participate in tourneys.