I thought both 6a and 7d were easy enough..........
The intention was apparent in 7d, but I might quibble though over whether "four" sounds like "for"?
It doesn't the way I say the words!
This is all most interesting, but being a bit dense I do not quite follow! What is the actual answer to 7dn, 'Dull-looking quartet said to be ruined', (4,3), D??????, ?