He is explicitly told to obtain one pair of unclean animals and seven pair of clean. "Of every clean beast thou shalt take to thee by sevens, the male and his female: and of beasts that are not clean by two, the male and his female." Gen. 6:2You're wrong. Gen 9:3 refutes your assertion that unclean animals were always unclean.
See above, and Genesis 6. Note also that the word in the Hebrew refers to animals that are "filthy, polluted". There is nothing in scripture to indicate that God condones the consumption of filth or pollution. If so, where?That's true. Again, cite any law prior to to Lev 11 naming any dietary prohibition, animal, or plant.