A: Had Anderson moved to Light Heavyweight permanently after beating Irvin, do you think he would still be undefeated in the UFC excluding any fights with Jon Jones?
B: How do you think a fight between Anderson Silva and Jon Jones would go today? 
I think Anderson would have won the LHW title and defended it successfully. He is a once in lifetime talent moving to LHW would have only further cemented his legacy as the greatest of all time.
As for a fight with jones I feel that jones wrestling size and athleticism would be too much for anderson to handle although I feel silva is much more skilled fighter. 
I think he'd probably have done really well but no way he'd not have lost to any of the great LHWs we've seen since 08.
He would have made a great fight with shogun
anderson and shogun would be outstanding. I still want to see the shogun that fought machida and griffin fight jbj