I have about 6 clues remaining to solve.
Let me start with these 3:
24. End, tram, strike, definitely (3)
3. Countries? Figures to include Spain (6)
30. European city area overseen by doctor (4)
3 A five-letter word for figures, relevant figures, numbers of people, things etc commonly used in business, meetings etc, with the usual single letter for Spain inside. This will give you 'Countries'.
I agree with you regarding the lack of answer lengths in IQ, hankir.
If it helps, the first row has two 6 letter answers. The next row begins with a 7 letter answer, followed immediately by one of 4 letters.
The first down answer is the 'Tchaikovsky...' one (12 letters, 2 words) def a colour, and it fills the second column.