How can you compare learning science to shaking a lulav? Shaking a lulav is a chiyuv, and is the only way to be mekayem that particular chiyuv. You admitted that studying science isn’t a mitzva per se, but rather a way to be mekayem the general mitzva of recognizing and loving Hashem. Couldn’t a person fulfill this mitzva – at least on the level of strict obligation – without going to college?
So again, what right do you have to be mevatel your chiyuv of Talmud Torah to study science? Shouldn’t you at least finish Shas and Poskim first?