Here are the potential errors and correct answers for the identified sections:

### ERROR IDENTIFICATION
1. **Question 1:** He'll be the active director until they can appoint a permanent one.
- **Error:** A. until (correct)

2. **Question 2:** Their achievements have already been analysed on depth and do not require further discussion.
- **Error:** C. on (should be "in")

3. **Question 3:** Tournament organizers need to offer large money to attract the top players.
- **Error:** C. large (should be "a large amount of")

4. **Question 4:** By the time he was nineteen, he had taken it big in the music business.
- **Error:** C. it (should be "off")

5. **Question 5:** Another problem that is tied up with underpay is the late arrival of benefits.
- **Error:** B. underpay (should be "underpayment")

### PHRASES, COLLOCATIONS AND IDIOMS
6. **Question 6:** It isn’t often ______ her employees compliments, so you should really feel proud.
- **Error:** A. she takes (correct)

7. **Question 7:** Union leaders are considering the company’s proposals to change working hours, reduce overtime, or impose a freeze.
- **Error:** A. money (correct)

8. **Question 8:** He was earning £215 a week before tax: ______ pay, £170.
- **Error:** A. make-work (should be "net pay")

9. **Question 9:** For Jackie, I’m afraid, money is always of first importance and the children ______ a poor second.
- **Error:** C. come (correct)

10. **Question 10:** ______ a lot of good that did me, spending all that time carefully wrapping the ceramic mugs only to drop the box on the floor and break them all.
- **Error:** A. left (should be "That")

11. **Question 11:** We made some changes around here.
- **Error:** A. high finance (correct)

12. **Question 12:** It was that little noise and a ______ that let me know that you were very proud of me.
- **Error:** C. big hug (correct)

13. **Question 13:** I looked up from my newspaper and there he was, Tim Trotter!
- **Error:** D. great (correct)

14. **Question 14:** I was ______ in the advanced class, so I moved to the intermediate class.
- **Error:** A. out of sight (should be "out of my depth")

15. **Question 15:** On the day of the party the table was loaded ______ food.
- **Error:** B. with (correct)

16. **Question 16:** Don’t keep all those chocolates to yourself - ______.
- **Error:** A. share and share alike (correct)

17. **Question 17:** You may very well be asked what your weak ______ are. Don’t try to claim you don’t have any.
- **Error:** C. points (should be "points")

Feel free to ask for any further assistance or clarifications!