Std gap for plugs is 1.1mm, you would only go to .8mm if your running a bit of boost with std coils. If you have Splitfires 1.1mm should be fine.
When you pull the plugs throughly check the porclien for cracks, it happens sometimes. And check the coil pack harness earth.
If you know someone with Nissan Data Scan just to check for fault codes, may be of help. I have it but you are up there, you may know someone at Nissan in Launy that may be able to check it for you.
Lots of things can cause a miss, A/F meter, BOV, fuel sys etc. It's a matter of being patient.