Cryptic crossword No 3,320

Across

1. Famous plumber's nemesis is a kook aping intoxication (4,5)
2. In 2026, it will be 250 years employment (5)
3. Down under, they pronounce nice "neat" (2,3)
4. Micky Dolenz lost 3 original members and speaks poorly of remembrances (9)
5. Fermat theorem's second hypothesis: If you bet this to risk it all, you bought this to end it all (3,4)
6. Insured? No, no, none at all. Absolutely (1,4,2)
7. The star of Jurassic Park deleted abbreviations of "despot" and "immediately" from the official word list (9)
8. Use the emergency room switch to bring into existence (5)
9. Remove what your former partner left on the peloton (5)
10. Malign men that are holding formation (9)
11. Carelessly overuse great works (7)
12. For example, B. Obama, with hesitation, he is one who more than just tried marijuana (3,4)
13. Somewhat of a poet, he quoted a bird (3)
14. He won't arrive to snack without returning (2-4)
15. Revolutionary South Korean singer traded places for his soul (6)
16. Nestle is down, a bit of chocolate gone missing (3)

Down

1. This poem's about a particular frog refusin' to do lawn work according to Spooner (3,4,3,5)
2. Advocates for internet-order brides (8)
3. Attraction is everything you heard about (6)
4. Prepares to twerk resulting in some pure arse shakes? (5,2)
5. Regularly imbibes - "bottoms up" - to make a point (7)
6. Moribund toddler eating a groovy cake (5)
7. New issue of Times listed things on the agenda (5)
8. Traditional celebrations occur when two Asgard heroes clash (8,7)
9. Grotesque underling's exterior is a front for an analytic interior (4)
10. Fair share results in nonlethal force (4)
11. Please return the rooster to its perch on the crooked beam (4,4)
12. Socrates' end was, when viewed in retrospect, so so close (7)
13. Reaction to fast food comes from character of fast food (7)
14. On the 8th Mo burst naked according to prophecies (6)
15. Cry over minute of sadness (5)
16. Ooh, ooh, ooh, I know it makes evolution (3,2)