Relay clicking...check the fuel pump is running constantly. Also check the injection locking relay. Both these control relays are under the panel under the black cover, sandwiched in next to the ECU.
Head retorque: You'd be surprised how much the bolts can slacken. I think
@Andyquadra measured cracking off bolts for a retorque down in the 50lb/ft range.
If I had to drive it, i'd do so with the actuator rod disconnected so there was no boost and keep the revs down. Valve clearances...if you take the rocker cover off to set them why on earth wouldnt you retorque the head bolts? It's quite literally an extra few minutes to fully slacken each bolt and razz it straight back around to 70lb/ft. You don't need to drain coolant or remove any extra parts. If you don't have a torque wrench i'll courier you mine.
ETA, DO NOT loosen all ten bolts then retighten, loosen one then retorque immediately, then the next, and the next. Start at the middle bolt, inlet side, then middle exhaust, then up one, right one, down 2, left 1, up 3, right one, down 4, left one. Its a spiral pattern.