Hops = freezer
Yeast = fridge
LME = cooler the better. Will last a couple of years at room temperature but will darken.
Grains = dry and cool. Uncrushed grains will last for years. I see no reason why crushed grains will go off in 2 weeks. Think of flour; it is crushed grains and people use that for a couple of years. I can understand base malts loosing their diastatic power (ability to convert starches) quicker when crushed, but you are steeping, and all your extracting is some sugars and a little flavor - you should be good.