TftT Christmas Crossword report

Plunging into the clues (without looking at the solution notes unless I need to), and assuming that my notation is close enough to the norm:

Across
1 Nothing in blasphemy and religion shows sincerity (4,5)
GOOD FAITH O IN “God!”, FAITH – Ideally, we’d like the break-up of parts not to match the two words forming the answer, but if the result is a convincing surface reading, it can turn out to be the best way to go.
6 Princess and soldier tango, becoming one? (5)
DIGIT Di + GI + T – familiar components, but combined well, and with a deceptive definition.
9 Anger about Conservative after lie, leader lacking core support (7)
RIBCAGE ((f)IB,C=Conservative) in RAGE. A lively surface, but a definition which I understood rather than think is really accurate – if we agree with ODE’s “muscles of the torso, especially the lower back and abdominal area”
10 All-in-one clue’s ending left out anagram for ‘skin cream’ (7)
LANOLIN (All in on(e)* Strictly a component of a cosmetic, though that difference is unlikely to prevent solution, but I’m reluctant about using cryptic crossword jargon like “All-in-one”, even when you don’t need to know what it means to solve the clue. There are still plenty of people as I was c. 1986, who have worked out enough for themselves about how clues work to solve, but don’t know the lingo yet.
11 As laid out by Brecht originally? Yes and no (2,3)
AD LIB laid*,B – I’m happy to count this as an &lit/all-in-one and to hope that no-one needs telling what Brecht was best known for.
13 Notices a politician in pub, and makes allowances (9)
PAMPHLETS ((A MP) in PH),LETS – maybe a mildly squinty definition – if to let is to allow, then to let is to make an allowance, and the number of allowed things could be plural. PH = public house is a shade unofficial – an OS map abbreviation rather a definition in dictionaries (including Chambers) but seen in puzzles from time to time. Stretchy def, I’d say – there are meanings of “notice” that could be a pamphlet, but most seem something shorter.
14 Critic rode roughshod over extensive field? (9)
DETRACTOR TRACT inside RODE* — I don’t think a full decision was made about the story being told here – if “ride roughshod” is the usual metaphorical version, an “extensive field” suggests a huge amount of criticism when “tract” could have been a publication, or something like “writer’s work”.
16 In vast territory a Shah reportedly … (4)
ASIA A + “Shah” or “A Shah” – either way, the homophone doesn’t work well enough for me, as the vowel in “Asia” is normally a schwa, and the one in “Shah” isn’t …
18 … killed a vast number (4)
SLEW … but maybe this pair of clues was from one person, attempting the tricky feat of linking two surface stories together. This double definition works well as part two.
19 Managing deliveries, tricky bit’s to score? Not so! (9)
OBSTETRIC (bits to score less “so”)* – I think a cricket surface is intended, but it took me a while to see what I think was meant by “score”.
22 Not got to the bottom of Horner’s pie, say? (9)
UNPLUMBED I can’t see that the second of the two definitions is really right – I don’t think a question mark is enough to allow a noun to be read as an adjective applying to it. Later addition: the “unplummed” idea was understood, but I didn’t agree that “Horner’s pie” (noun) could define it. With something like “like Horner’s pie”, it would have been fine for me.
24 Mean, spotty person’s first to leave (5)
IMPLY (p)IMPLY – not mad keen on “A’s first” meaning the first letter of A, but I think it’s comprehensible.
25 German abridging Lion King’s cool as a cucumber (7)
GHERKIN G=German, HER(o),KIN(g), with “cool” in its informal excellent/acceptable meaning making “cool as” a rather ingenious linking phrase between wordplay and def. As G=German is only in Collins, it’s not a favourite one-letter abbrev.  Alternatively, as intended, HER(o),K=king,IN=trendy=cool.
26 Stirring treacle well it becomes complex (7)
ELECTRA – treacle* – but I can’t see that Electra or Oedipus alone mean the same as they do with “complex” added, or that “complex” convincingly describes something stirred, so in a real puzzle scenario I’d be suggesting or requesting a different clue.
28 Bows and bouquets (5)
NOSES A double definition which needs the “smell” meaning of “nose” and the bows of multiple ships to be seen as the same thing as the noses of multiple aircraft. This seems OK, but it was a post-solve parse for me.
29 Cathedral city with botched burials in backward, unknown quarter (9)
SALISBURY With “quarter” as the direction of compass point, “backward,
unknown quarter” gives us S,Y in which to place “burials”. Especially in a world where “city” may indicate Ely or Wells, I think “Cathedral” could be fairly omitted, but maybe the idea was to suggest historical grimness.

Down
1 Fish net is below deck (7)
GARLAND GAR=fish, NET=land=secure (vb). With “is below” as the only words actually meaning what they seem to mean, this is a pleasingly deceptive clue with a good surface reading.
2 British men first in basketball, for example (3)
ORB OR=men+B=British, with a basketball as a sample “orb”.  B as a possible “first in basketball” is a presumably deliberate false trail.
3 Lover carries book to university holding a torch (8)
FLAMBEAU A in ((B in FLAME),A) – I liked the idea of a (would-be) lover holding a torch, though if that was a deliberate idea, we might as well use “carry” as in the usual expression about it. Later: we would of course need to replace the “carries” earlier on.
4 I drink noisily? Chill! (3,2)
ICE UP – “I sup” which worked fine as a homophone, but for this to mean “chill” rather than “show the results of chilling”, we seem to need a definition from the American English parts of Collins online, which is supposed to be where we don’t go.
5 Signs of heartless hoaxers taking in every possible victim (9)
HALLMARKS (ALL=“every possible”, MARK=victim (of a scam)) in H(oaxer)S, and hallmarks=signs as distinctive features, as in “deceptive definitions are hallmarks of good cryptic clues”
6 Little craft but not good housekeeping initially in home improvement (6)
DINGHY – N,G,H in DIY=“home improvement”. I’m not sure exactly what the surface is telling us, but it’s enough to take us away from the true meaning of “craft”.
7 Drugs openly used as a sweetener (6,5)
GOLDEN SYRUP – (drugs openly)*, with “sweetener” = bribe in the surface story.
8 Great if French fan turns up in this country (7)
TUNISIA (A1,SI = (if French),NUT) all reversed – with “if French” as fair as “the French”, and the pleasing but presumably incidental point that if you go there and have little Arabic, French is very useful indeed.
12 Character pursued by journalists to provide some elevated words (11)
LETTERPRESS LETTER+PRESS – nicely artful definition, letterpress being the proper printing version of your old John Bull printing set – a raised surface for the printed image and ink applied with pressure. On the other hand, “character” is as discussed in the 27D comment.
15 Starting to realise old metal remains are brass (9)
TROMBONES – T R O M, BONES – for me this pushes “starting to” a bit too hard, and I’d prefer “Starts to realise …” which makes it clear that multiple initials are needed. But thanks for the nod to my main spare time activity these days.
17 Delicatessen I re-establish, sandwiches on the counter – uncanny quality (8)
EERINESS – Full marks for attempting an 8-letter (reverse) hidden word clue, but the definition following a hyphen as a bit of a give-away separator is one of those defs that could be added to many beginnings. In a real puzzle scenario, especially knowing the clue type for the next clue, this seems a candidate for trying something different.
18 Stung unpleasantly? Yes, partly, by one of these perhaps (4,3)
STUN GUN – hidden in the first two words, and the story told is very convincing.
20 Softie is keen on sweetheart (7)
CRYBABY – I like “keen on sweetheart” for CRY,BABY but I’m not quite convinced that a softie is a crybaby.
21 Scene of game with outspoken disagreeable fellow (6)
RUCKUS – RU = game, “CUSS” – a homophone that seems close enough. This is arguably fussy technicality, but I think multiple adjectives for the same noun are a weak point in clues – the fellow could be just outspoken or disagreeable as far as the surface reading goes. This is mostly avoided in this puzzle — the “mean, spotty person” in 24A and the quarter in 29D are the only other examples I can see.
23 Striking over pin – fifty remain (5)
DWELL – D(o)WEL,L – a dowel is usually a peg in dictionary definitions, but can also be called a “dowel pin”, supporting common sense. As the L indication, “fifty” is pretty easy, and I can’t see much of a surface story, so I think I’d have looked for something else.
27 Character up at university (3)
TAU – AT<,U – Definitions for Greek letters are pretty much restricted to “character” or a synonym, or the well-worn trick of indicating the relevant letter in a word that is clearly Greek. So this was a bit of a thankless task, and the writer was probably well aware that however hard setters try to convince us that a character is a real or fictional person, they will usually fail when the solver is experienced.