When to replace tires?
 

I have 3/32 left on the rears and 5/32 on the front. I know 2/32 is the legal minimum, but am I reaching a point having potential safety issues at 3/32 or should I run them to they hit the wear bars?

well, does it rain a lot where you live?

I replace my tires once I see cords.

Not everybody uses track days to get rid of the last 1/4" of tread though. If you are losing traction due to low tread, get new tires. Unless your tires sucked in the wet already, in which case they put wear indicators there for a reason.