1. Indefensibly
2. Stunt nuts
3. Overtime pay
4. Each word can be anagrammed into a female name: Rose, Mary, Olga, Della.
5. Undergo, guerdon
6. 72. (Each top number is multiplied by 9 to get the number below it.)
7. Why do Poly and Ester put their names on so many clothes?
8. Charlie is six and Pat is nine.
9. Plymouth, Trenton, Chicago, Phoenix, Albuquerque, Seattle
10. Ter, let, date
Bonus Answer: Franz Liszt invented the tone poem in 1840.