The keys do the EXACT same thing as cranking the bars. So it would be 2" MAX
Yes after you put them in but you can crank them and get more lift out of them, for a little bit i was ridding on 4" of lift from keys alone.
The superlift kit comes with a block for the rear no shackle.
He can obtain 7" of lift in the rear from the 3" block a 2" shackle and a AAL.
In the front the Superlift its all drop brackets. he can put in lift keys and get some lift out of them id say he can probably get 6" of total lift out of the front with the superlift setup lift keys at full crank.
I doubt he did it though if he's off roading the CV's would be shot. my CV's were binding like crazy when i used the lift keys. but it is possible.