I didn’t detect any over-arching theme in this puzzle, although the appearance of the word NINA in the sixth column could well mean that I’m missing something.
Across
1 HUM,MIN(GB,IR)D
9 W,OR,SE – “facing” as in the compass opposites of those in the clue itself.
10 LI(MESCAL)E
11 MUESLI BAR – (a sublimer)*. Not being a health-food freak myself, I’m glad that Araucaria saw fit to qualify the &lit-ness of this with a question mark.
13 TEE,MING – “tea”; again the question mark seems appropriate, to flag the mental leap of China=Ming
15 E(YE)D – solvers =”ye” is atypical piece of Araucarian jiggery-pokery.
18 PE(THAT)E – one for all the schoolboy humorists out there.
24 PAU,LJ, ONES – a (presumably flirtatious) dance of yesteryear.
27 M,OVER – ….as in movers and shakers.
29 THEM,A,NO,FLAW – fortunately I’m better at bluffing my way in Chaucer than Shakespeare, so this one came quicker than it might have otherwise.
Down
1 HAW(KM)O[-r]TH – again I lucked out on the literary reference. The only reason I know that the Bronte Parsonage is in Haworth is because my grandmother used to have table mats featuring “The Historic sites of Yorkshire”!
2 MURDER,ER – (Re Red Rum)< A similar device helped to form the denouement in a Listener Crossword a couple of years back.
3 I,DEAL – ref. the card-playing convention; “You cut, I’ll deal”.
4 GOLF, BAG – “upbeat” = flog<
5 I,M,MERSE[-y]
8 GEE-GEE – the central letters of “dogged”.
16 CAR,NIVAL – not quite sure what purpose the is served by the phrase “coming up” .
17 BED,STRAW
19 DE(PLET)E – where “some droplets” is ther contents indicator.
20 PRUSSIA – I’m guessing that the colour Prussian Blue can be obtained via some sort of acidic reaction.
21 SPUR,GE
25 JUMBO – the second half of mumbo-j.
Don’t have the FT, but the pair of 1s suggest a lepidopteran theme. The hummingbird hawkmoth is a rare and beautiful sight on buddleias (when they’re out), in these northern latitudes at least. Bedstraw and spurge may be specialised food for other winged creatures.
Re 15A. “[C]oming up” does not seem to be a reversal indicator. It is probably intended to be a position indicator. The whole clue seems to suggest that the word ‘car’ is on top and ‘nival’ is below – in that order. The word ‘nival’ was new to me. I find that it does not mean ‘snow’ but “of, or growing in or under, snow” (WNW Dictionary on my machine: I don’t find it in any other desktop dictionary that I have). Perhaps ‘under’ does double duty as part of an accurate definition.
BTW, when did I see snow in my life? That was one morning when I woke up and looked through the window of a log cabin on the Black Hills of South Dakota. I was past 50 years of age then.
Sorry for the lengthy posting.