ACROSS

 1  On the pavement, you’ll see a snake! Stop! (7)

 5  How hot air might come to you–or something that runs over the valley. (7)

 9  You don’t want to have things come out this way–you’ll see it in certain people–aka Generals. (7)

10  Cut a bit off to do it, and in Paris it returns in a clipped fashion. (7)

11  Good employees shouldn’t do it to clock what might be a small version
of the clock. (5)

12  One of the lowest digits, if you get to a point here. (3)

13  By the sound of it to inter a straw type, or a rasp type. (5)

14  The answer might be rotten, but you’ll find it a small island indeed! (7)

16  In a cross-wind, less likely to be what you don’t want someone to do to you. (7)

18  If you hear 11 with the birdie, someone may be getting ready to shoot you to make it! (7)

21  How could a mess of gruel be so responsible for one of the above? (7)

24  A relatively high spot characteristic of Greece? (5)

26  and 17 down Where many a person works away from the frozen surface. (6)

27  and 15 down A polite expression at the revolving door. (5,3)

28  The specialist medico is evidently told to go ahead with a rush! (7)

29  One’s former mate has plenty, for instance! (7)

30  She gets the sort of heat you can use to carry your arm in. (7)

31  Eased a test situation, to show how one calms down. (7)

DOWN

 1  Everything was due to being permitted. (7)

 2  Adaptable, or maybe phony, as shown in blurry last pic. (7)

 3  What the determined partygoer looks for to destroy self-confidence. (5)

 4  Come down heavily with your feet, and in Paris getting up in it to be given something nice. (7)

 5  Ships containers. (7)

 6  A lousy performance, but a deadly thing to drop. (1-4)

 7  A complete description to the news boss, in short, it is said. (7)

 8 An old photo shows what the steno might do following the money in London. (7)

15  See 27 across

17  See 26 across

18  Getting quiet, lifts up encomiums. (7)

19  An exclusive group with the lake bed turned over. (7)

20  Do 7 without the boss, as part of the noun, certainly. (7).

21  With one’s hands, bangs the sideboards. (7)

22  Commonly deteriorate what the gardener might do to plant things. (2,2,3)

23  With a great letter you get the word for lavish giving. (7)

25  Improperly teach a swindling type. (5)

27  A pull-up as a prize. (5)