My staffie has a Bubble like Scab on the end of his right ear, sometimes it bursts randomly, it has been there since i got him is it just a scab or can it couse permentant damage?

Think it should be looked at, particularly if the ears are white. It could be ear mites and the scratching or shaking has caused a haematoma. Could also be the sight of a bite that is infected.

His ear looks fairly normal in colour till it comes to the giant scab, could this totaly screw up his ear?

No way of knowing what the trouble is via the internet, it need a vet. If the dog has white ears it could be sun damage if it was tied outside without shade but a bite or an ear infection is more likely.