Card 6
Turns/torus/tyres etc, based on f"'s answers and guessing the most likely results for t?r?s. Much less conclusive when I've read the clue properly. It looks like they may all be 5 letter words
Card 7
Guessing that determin. means take the determinant, and that a=1,b=2..., the determinant of the matrix is 125239. This makes abebci (or lebci, aybci, or abewi), which is an anagram of cabbie. Not sure about this, because it seems to ignore step 2. Lebcis seems to be a name, but no anagrams that I can find...