Depending on your rev limit the 120mm pulley makes 10 psi, their 8 psi rating is at 7200 rpm with the smaller g2 blower, even then it's closer to 9 psi. At 10 psi I'd recommend no more then .028 from my personal experience. It's not causing your rough idle but just figured I'd point that out...
Plugs should be at .028 at that boost level but I'd check the vct cam timing while it's running rough compared to when it's running smooth. It's probably erratic pointing to vct solenoids or phasers.
You should see the in gear idle. I'd raise that to 750 and the park idle as well. The other adder tables that are less then 750 make them that as well.
They can be bent but they also can crack. Sorry I know that's not much help.
If I had to bend it I'd remove the plastic fitting then slide a pipe about a 1/4" wider then that pipe over it down towards the base then slowly bend it over.
That is 100 percent the coyote "tick". Like mentioned though it's way more common on gen 3 cars. I've actually never heard in person a gen 1 or 2 car do it, only in a video like yours.
Since you're boosted and probably already running the proper timing for your fuel you probably won't benefit much from anymore advance but you will see longer life with them and less high rpm misfires. It might not be something you can feel in the seat but it would be shown on a dyno.
Use the m50a motorcraft spec ngk plugs. They come gapped at .030 so closing all the way down to .022 if needed is acceptable they also come with an electrode arm designed for boost that is much stiffer then the 6510. The reason you're seeing inconsistent gapping from the 6510 is because of the...
The 6510 is the stock heat range for the gen 3, it is one step colder though for a gen 2 car like mentioned. Either way a 6510 should not be used for boosted combos because out of the box they come at .044 gap and ngk never recommends closing the gap more then .008 it causes the electrodes to...