Tyre wear

[w3it]

Hi
My two rear tyres look fine and have a lot of tread on them However, when taken off, the inside edge is almost worn away! They have to be replaced. Is this normal?

There is a noise from the back. When driving straight it is fine, but slightest touch on the steering and there is this sound that something is rubbing. On inspection there is nothing that appears to be rubbed. Any ideas? Think this is related to the tyres?

Thanks for any help.