QUESTION: If I change my NOMP code to create Empty Blocks (with only the coinbase transaction) will I get around the problem of other (SegWit-compliant) nodes considering my block as invalid?
there's nothing to get around, segwit being activated won't invalidate your block. pools were mining non-segwit blocks long after activation, they probably still are
after all, segwit was a softfork, that means everything that was valid before is still valid afterwards