Professor has a hand in this couple having abusive relationship (5,3,4) = PUNCH AND JUDY
cryptic def. The puppeteer of a Punch and Judy show is known as “professor”.
Got these two from the checking letters/definition but had to look up the construction at Big Dave.
Bring up without favour for the major part (8) = DISINTER
without favour = DISINTEREST, for the major part = most of a word
Attitude in which is example (6) = STANCE
example = INSTANCE