12d Anagram (shifts) of hire + m (first letter of mercenaries) + double. Homebuilder as in Barrett, Wimpey
21d Tutting, expressing disapproval, dropping NG, no good
17a Hog is corner, as in corner the market, plus W (with) and ASH (tree)
1d. Stuck is fast, set in rigid position, dropping S (son). Tuck as in tuck shop