Hi Bagpeel and welcome!
Hints…
6a The answer to 4 is the definition. The remainder implies the solution is a palindrome.
15a A cryptic definition. The runners being of the vegetable variety.
16a Anagram. “Fancy” is the indicator.
15d Also an anagram. Here “badly” is the indicator.
Full explanations of all the solutions are given here, as they are each Sunday one week after publication…
https://www.fifteensquared.net/2025/02/09/everyman-4085-2-february/
Hope that helps. Keep going!