in the last week of flowering it wont hurt the plant to cut off all the fan leaves, because your plant has stopped growing and is just ripening the buds
I'm not even close to an expert in sativa propagation, but I had a question concerning this comment. We all know that plants make their food by using the nutrients uptaken by the roots and using light energy to chemically rearrange these elements into simple sugars (photosynthesis). Why remove the major portion of photosynthesis (chlorophyll in the leaves)? Just because a plant isn't vegetatively growing, it is still growing sexually by making more flowers and developing existing flowers. I feel that removing all the leaves from any plant, including sativa, will stress out your plant and stunt its developement. If I am wrong, please feel free to correct me. Hehe; like I said, I am not an expert, but do know a little bit about plant growth.

Maulrat