Not too tricky, by Cinephile’s standards, with the Jane Austen mini-theme being familiar enough that even a lit-twit like me could twig it early on. Having just logged on to post this, I see that - between this and the Guardian - our setter seems to be enjoying a literary double-header today!

Across
1 PE(SET)A - I wonder which pre-Euro currency will prove the most enduring in crossword spheres? Probably the Mark, for its sheer versatility, I assume.
8/9 WILL,I,A,M(W,ALL)ACE - aka “Braveheart”
11 PERSUASION
14 AMMONIAC (o can maim)* - I’ll grant you “nothing”=o in the anagram fodder; but “user” as the anagrind itself?
16 NON,SENSE - Lear here is Edward, rather than King. Also, a thematic reference to S. & Sensibility.
18/21/22 NORTHANGER ABBEY - The idea here is “Naughty” (homophone) around hanger and abbé.
20 EMMA - “Pip” is meant to point you in the direction of Pip-Emma - which, along with Ack-Emma, is/(was?) military abbreviation for PM/AM.  Strictly speaking, I suppose they’re actually clarifications rather than abbreviations.
21 ARTIFICIAL - CIA in (airlift)*. Good surface, for those who remember America’s attempt to spring their hostages from Iran in the late 70’s.
24 SECOMBE - “seek ‘em”
25 KUMARA - (a ram,UK) rev. I somehow remembered this obscure answer, but god knows how. Maybe a brain fragment from a long-lost Listener or Azed?

Down
1 PRIDE - thematic
2 SILESIA (liaises)* - a region of Central Europe that, as anyone who’s ever played the game Risk will attest, one ignores at your peril.
6 SALT,PAN - a well strung together surface.
13 ST(OR,MC)OCK - the only unfamiliar answer to me, but readily deducible. “Medal”=MC/Military Cross.
15/12 MAN’S,FIELD,PARK - I don’t usually get pedantic on Libertarian definitions, but “where the cars are”=park seems like a stretch. For instance, if you invited me to attend the “Proms in the Park”, I would be a little miffed if we ended up sitting in a multi-storey conrete parking facility.
17 S(TAD,I)UM

A literary romp from Araucaria - five of the down answers are the names of books and there’s at least two more literary reference among the clues.  Great fun, just a shame that once I’d got the four long down answers, the rest of the puzzle fell into place a bit too quickly.

Every clue hear is worthy of a mention, but I’m not allowed to blog them all, so here are the most obscure or noteworthy.

ACROSS

8 ASHPLANT - PLAN in (hats)* - An ashplant is a type of walking stick, presumably made from ash?

10 RUS(S(om)E)T - both RUST and RUSSET being shades of red

12 LYRA - a constellation and the principle character in Philip Pullman’s “His Dark Materials” trilogy.

13 GOLDEN WEST - OR=golden and W=west - the reference is to the Puccini opera, La fianculla del West (The Girl of the Golden West)

15 KNEES-UP - (keep sun)*

16 P.T.O.-LE-MY

18 S(eptembe)(C(H)OOL)(YEA)R - this clue doesn’t work for us Scots, since our school year starts in August.

22 A-V-A-TAR

23 MEDICI - relating to the Italian family, and to Browne’s most famous work, Religio Medici (The Religian of a Physician)

DOWN

1 A STUDY IN SCARLET - (Cindy us)* in A STARLET - the first story to feature Sherlock Holmes

2 (n)A(PASS-AGE)TO-IN-(<=AID) - by EM Forster

3 PAN-TAG-(c)RUEL - by Rabelais

5 (g)OD-IN - not Ximenean, but typically Araucarian

6 A FAREWLL TO ARMS - disappointingly obvious

7 (b)ACH-(b)RIST(MASCAR(a))OL - much better

14 EXTIRPABLE - (tip be relax)*

17 HEAL-THY - brilliant - “Physician, heal thy self”
 

A quickish pleasurable solve with a couple of tricky clues and new words (for me). Once I’d found some of his well-hidden definitions, Dac’s cluing left no doubts for even the toughest of the clues. There was a handful of drink-related answers and clues though not enough to suggest a theme perhaps.