Possible Clues:

• Feline selfishness increase showing class
• Tom, maybe, with self-confidence increase in class
• I rebel after pussy is put in a box?
• Self-confidence to increase after guy is put in class
• Tom English is taken in by butchery class
• Moggie's selfishness issue displaying class
• I agree cost is incorporated in order
• Classify
• Kit is taken in by European and US politician in class
• Tie cargoes roughly and put into boxes