Once you have verified your ledger does that mean it is 100% safe. A tampered with ledger and cannot be messed with?
There is no set up in the world which is
100% safe. There is an old saying:
The only truly secure system is one that is powered off, cast in a block of concrete and sealed in a lead-lined room with armed guards - and even then I have my doubts.
Once you have verified your Ledger, you can be as sure as possible that it is legit, has not been tampered with, and is safe to use. Thousands of users use Ledger devices, and as far as I am aware, there has never been a successful hack which didn't also involve the user doing something stupid.
I know the privatekey stays on the ledger but is there anyway it can be read by anyone?
Yes. As I said before, nothing is 100% secure. With a powerful enough electron microscope, the knowledge to use it, and enough time, you could extract the private keys or seed from the secure element. Is this possible? Yes. Is it likely? Absolutely not.
Provided you follow the proper steps when using your Ledger, the chances of someone else accessing your private keys are negligible. If you are still worried, then you should also consider using a passphrase which you manually set every time you use your wallet (known as a temporary passphrase, more information here:
https://support.ledger.com/hc/en-us/articles/115005214529-Advanced-passphrase-security). Because neither the passphrase nor the seed it derives are stored on the device, they can't be extracted.