Thanks for the responses guys! I'm developing some stuff that's pretty important, so I'm using all recently-bought and fresh chemistry, but I may try experimenting with storing some chemicals in the fridge for a while and seeing if that effects anything.
Chip -- I've got some other chemicals I was about to throw out since they're about a year old unopened, but since you've tried unopened chemistry that's a couple of years old without anything noticeably negative, I'll go ahead and keep it to see if it's still okay. That'll save me at least $100, so thanks for that.
John -- Thanks for those links. Now that you mention it, I think I've heard of R09, but I've never used it. I just ordered the Photographer's Formulary's mix of Rodinal the other day, and like the R09, it's the "pre-war" formula (I don't know how old the Rodinal formula is, so I don't know for sure which war that refers too). From what I've heard though, the pre-war and post-war/updated formula from Agfa functions almost identically, so whenever the Agfa Rodinal well's run dry, I'll be playing with R09 and Photo Formulary's version to see what difference there is, if any. And absolutely, I learned my lesson about the safety goggles when playing with pyro (splashing that in your eye HURTS!!!), and so now whenever I mess with chemistry in powdered form, I put on a dust mask, too. Even if it's not as wicked as pyro, it can still mess with you.
Thank you both for the help!