I trim the rhind off. However, i make a concerted effort to remove as little as possible but still get rid of, most of, the hard dark spots. Some will remain in nooks & crannies, dont worry about that. I have read that some dont trim @ all. After the ribeye is steaked out, I remove the tails, as well. If not, that solid piece of fat will cayse major flare-ups.
I have been getting my ribeyes from SAMS with good results. No COSTCO near my area.
I hope this helps.