The appearance in the (white) light of the unprocessed paper doesn't mean much. To test it, cut a piece in two, develop and fix one, using the normal times you would use for your chemistry. Only fix the second one. Compare them in the light, if it's fogged you'll know, then you can decide if you want/need some benzotriazole, or not, or just make photograms. If you want to be very thorough in your testing wash and dry them, then compare.
As for curling, most double weight fiber paper will be curled, even fresh, it's curled.