I get 10 or more pounds of green coffee beans (Colombian Supremo) in a 'burlap bag'. Should I freeze the lot of them for a few days to rid them of potential pests?
You failed to give us any details about the variety, provenance or history of your green coffee beans. Nor did you elaborate on what kind of potential pests you are worried about so all we can do is speculate vaguely.
The only likely pest to be found in green coffee beans is the coffee berry borer, Hypothenemus hampei. This is a tiny, 2mm black beetle. And legitimate green beans would invariably have been fumigated to eradicate this pest.
Drying green coffee beans to critical water content levels, followed by freezing @ -15C for 2 - 6 days appears to be an effective alternative to fumigation. However this would normally be redundant to fumigation that has already taken place. And there remains some controversy about the impact of freezing upon cherry quality.