First thing, check firing order, I know you have checked it, but humor me.
And make sure #1 wire goes to #1 cylinder, and #2 wire goes to #2 cylinder and ect......................
1.5 turns in is correct from 0 lash, 0 lash is when the rocker can not be lifted off the valve stem by hand, so you loosen the rocker nut until you can see/feel a gap between rocker and valve stem then tighten it until gap is gone, 0 lash, THEN 1.5 turns in.
Yes this adjustment would be made on both exhaust and intake valves when that cylinder was at the end of compression stroke TDC.
The 1.5 turns is to compress the hydraulic lifter to it's approx. 1/2 way point, you should still be able to turn the push rod by hand after this 1.5 turns, it's hard but should turn, if you can't then it is too tight something is wrong.