I would suggest to limit who plays on your account or find a way to keep track of who is. Best option is to not let anyone play on it at all, just my advice, but your appeal has been accepted and you have been unbanned.
i see the OP gear as a way to take money out of the economy.
make it so when you die you lose money an xp. this would mean creating/finding a bank plugin. players would be able to depo and withdraw from this bank one for xp one for money this would give some incentive to go hunting other players/ pvpin general. So players would keep items but lose the money and xp they had on them. also possibly adding a shop that players could buy OP items swords and or gear.
so u can lock colored shulkers just like a chest?
I agree with there are other spawn eggs in the crates pandas should be added just a very rare chance just like wild.