my car has seen 10+ HARD pings. I think it sounds like a marble in a tin can bouncing off the bottom..

somehow it's still alive, compression hasn't been adversly affected either.

Hopefully I never see another.

So next on my list is the fuel pump rewire, this should ensure that im getting enough fuel to not be leaning out right? And should i bother getting an A/F guage? Or should i just wait and get the car on a dyno with a wideband?

How much would i be looking at spending to get my car on a dyno anyway? Ive never gone to one before

Is there a certain RPM range that detonation can occur (i.e. idling) ?

i wouldnt worry about it at idle since there's no load on the engine. you shouldn't be detonating at idle. if you are, i would think you have some fuel issues. detonation is most harmful at higher rpms (loads) i believe.