you dont need to clean your registry EVER , you may neeed to defrag or compact it , that CAN help , but clean it?? nah .. dont beleive the hype from the reg cleaner companies its rubbish
I dont like Norton , but thats just me , my hatred goes back to the day it was a system hog , its not anymore , we have 360 at work and i was pleasantly surprised and i know thw Antivirus is second to none (except Eset

)
however if i were to use Norton id stick with the basic internet security not 360 , they work too hard to make 360 idiot proof and give you very little control over what it does , but its your money :P