How can I make my iPad more PCI compliant?

Okay, so I’m wanting to use a few iPads as point of sale tablets and process payments from cards. The back-end is all setup via a reputable and compliant web service accessible through a web browser. But my devices needs to meet certain criteria to be allowable to be used. That’s where I need help.

“Restrictions” helps a lot. But I need to be able to do more to secure the devices. Like:-

1. Prevent hot-spot being used to share the internet connection with other devices.

2. Prevent the devices from allowing screenshots to be taken when HOME + POWER is pressed.

3. Prevent messages/mail being sent. Removing the entire apps would be ideal.

4. Hide or remove the settings app. Or at least prevent ANY changes to it.

I’ve seen devices that implement some or all of these things. But I can’t see how it’s possible.