ok why is this even allowed ? (housing)

[Valkyrie_Lenneth]

Looks like they need to add a term into the game that only allows 1 house on the world per account so Jenova characters could only get one house even if they got 50 characters or whatever and same goes to every character but a account should have a lock of a maxium of 10 houses total that would prevent stuff like that

That exists already. This is an fc house, which is different. Unfortunately, you can still get multiple fc houses, especially if it's a different account that buys it, then makes the other account leader.