I didn't mean to imply that the moment you expose chips to humidity that you need to bake them - my understanding is the same as that of others above - you have a window of time, dictated by the MSL, that is cumulative from the time the original seal is broken until the components must be baked. You can take and remove the components from a dry box multiple times during that time, so long as you don't exceed the total amount of time exposed to non-dry environment per the MSL.
I just didn't know what MSL the parts you were using were subject to - some of the more strict levels are quite short. I manufacture my own in-house products, so I don't really need to stick to any sort of documented standards, just thought it may be an issue if you were offering contract manufacturing services.
RE: Air. IMO, air requirements are like power requirements. Something "needs" 10 CFM like it "needs" a 20A breaker. The machine might pull 20A at startup or under the worst possible circumstances, but in real world usage, it won't really use that much. Same with air. Vacuum venturis are inefficient, but PnP nozzles are very tiny... 10CFM sounds like a real lot, even with pneumatic feeders. If you have the luxury of getting the machines delivered and up and running with a cheap Home Depot compressor, you could figure out how much air they actually use before spending $$$ on a silent compressor.