autofire and arrarys
 

Ouestion to use autofire extra correctly,do i need to buy the extra for Each power in the array our simply its default power...or in this case maybe the devce itself.....to have it apply to the whole array??

You need to buy it for every power in my opinion. Otherwise, the math gets really wonky unless all of your powers have the same base cost. The treatment of modifiers on Arrays in Ultimate Power technically allows adding Extras and Flaws to an array as a whole, but I seem to remember Steve Kenson himself stating that he hadn't anticipated some of the side effects that resulted from doing things that way.