20 This is good: 'calcining flame' is good.
22 'dubs' is said to mean 'stabs', as it certainly means 'strikes'; but this seems to have little or no appropriateness here and to ignore the quaint conceit of 'commence' in its academic meaning. 'Women take their degrees by Cupid's dart: as the fact of being hunted by a king ennobles a hart.' Cupid = the King of Love.
24 'parole' too has a very delectable double meaning. This poem is really full of most excellent differences.
25-9 The lesson of the unregenerate Donne and the never-regenerate Carew.
32 gamesters] = 'fencers'. to seek at sharp] = 'not good at sword-play'.
33 'The sol-di-er'. By the way, did Butler borrow this 'iron' and 'environ' rhyme from Cleveland?
43 The apostrophating mania made 1653 contract to 'let's' and spoil the verse.
44 Th'] here of course = 'they'.