The sharp bits you knocked on the ends of the spark plugs usually don't cause pinging. It would however cause pre ignition which is much worse, but you would know if it has happened. As above, check the base timing it is probably over advanced, also the stock intercooler isn't to "more than stock boost" happy.
Also the ecu does have knock protection, but it isn't actually that good and iirc it doesn't do much to pull timing/add fuel above 4000 rpm
You may have a slight exhaust leak. sounds weird but I had that problem, sounded like pinging but turned out to be a sh*tty turbo/mani gasket