I just cant beleave that you are supposed to change your spark plugs every 7500 miles!!
My goldwing uses regular plugs and they go 25,000 miles inbetween changes and if they were Iridium, they would proably go even longer still.
Going by what I see in the pic's, you are using Iridium plugs. Thoses will, and do go 100,000 miles when in a car engine.
Does the verseys come with Iridium plugs from the factory???
As for the air filter, well that depends on were you live and ride. Here in Erie, the air is pretty clean
The engine dieing out or nearly dieing out at idle is not a spark plug problem, it is more of a fuel problem or possibly dirty throtle body(s)
Take a look inside the intake butterflys when the air filter is off and look for soot aroud the area of where the butterflys are when closed.
I am no expert, just my two cents worth of input