What do you mean by "item hack"? Items are handled on the server's side, so hacking to get items is impossible. There may however be glitches that your players are exploiting.
Sometimes, I can see some players who gived items them-self. But this is happening very very very very very very very rarely
i dont believe this, you should make sure it's not client sided first and can you actually USE these items
correct, need something like an eval/code execution rights the app itself may be worth a look if it's true