Fair progress this week but struggling to parse some of the long answers.
13a. One checks pulse or pulses after bad actor recoiled (17)
Electrocardiogram fits but can't see why, apart from the definition.
31a Supply fashion garments after working in northern town (8-2-4)
Must be Stockton-on-Tees. Can almost but not quite parse. Supply = stock, fashion garments after working = on tees, but left with an unexplained 'ton'.
20d Combatant one quickly smashed, admitting confusion (5,12)
Light Welterweight fits.