Across
Toxic chemical made by strange doc yearning to inhabit evil alter ego (15)
Copied data source from installation wizard (5)
I haven't cracked this one yet — but Fifteensquared have:
I <nstallation> (“source from” means first letter only) + MAGE (=wizard)
Oscar won by impersonator - ridiculous and irregular (9)
I haven't cracked this one yet — but Fifteensquared have:
O (=Oscar, in NATO alphabet) in [APE (=impersonator, mimic) + RIDIC (=ridiculous, colloquially)]; aperiodic means happening irregularly, infrequently
Reported great uncertainty in criminals' location (7)
I married a couple in cleric's office (7)
Join prisoner heading for execution in Hull (8)
I haven't cracked this one yet — but Fifteensquared have:
FUSE (=fuse, meld) + LAG (=prisoner, lag) + E <xecution> (“heading for” means first letter only); the fuselage is the body of an aeroplane, the hull that of a ship
Naked Yankee claiming length is something over a foot (5)
Rambler almost here after covering one kilometre (5)
I haven't cracked this one yet — but Fifteensquared have:
[I (=one) + K (=kilometre)] in HER <e> (“almost” means last letter is dropped)
Mufti's cryptically welcoming bishop with quiet greeting (8)
I haven't cracked this one yet — but Fifteensquared have:
[B (=bishop, in chess) in *(MUFTI’S)] + P (=quiet, i.e. piano , in music)
Pirate heard ribald melody (7)
Cold laugh and smile expressing dismay (7)
Public official is pals with spymaster embedded in Arab state (9)
I haven't cracked this one yet — but Fifteensquared have:
[BUDS (=pals, chums) + M (=spymaster, in Bond movies)] in OMAN (=Arab state)
Dictionary entry's origin in light Austen novel (5)
I haven't cracked this one yet — but Fifteensquared have:
L <ight> (“origin in” means first letter only) + EMMA (=Austen novel); a lemma is a word or phrase defined in a dictionary or entered in a word list
Find rodeo unexpectedly hosted by bubbly gay man (15)
Down
Elevation of inaugural location for Black King's castle (6)
I haven't cracked this one yet — but Fifteensquared have:
In a game of chess, the black castle/rook starts out in square H8, i.e. H eight, on the board.
Spooner's awful basketball shot is wasted (9)
I haven't cracked this one yet — but Fifteensquared have:
Spoonerism (“Spooner’s”) of “dread (=awful, frightful) dunk (=basketball shot)”
Repetitive ascending extract from twelve-tone nocturne (7)
I haven't cracked this one yet — but Fifteensquared have:
Reversed (“ascending”) and hidden (“extract”) in “twelv E-TONE NO cturne”; “one-note” means unvarying in tone or emphasis, monotonous
Bang on about cutting taxes endlessly regressive (5)
Tough quality of game stuffed with hock? (9)
He said sesame and lettuce in buns are burger amateur's toppings (7)
I haven't cracked this one yet — but Fifteensquared have:
A <nd> L <ettuce> I <n> B <uns> A <re> B <urger> A <mateur>; “toppings” means first letters only; the reference is to Open sesame , the magical phrase spoken by Ali Baba in Ali Baba and the Forty Thieves
Speaking in code I elected to abet uprising (5)
Avoided having key cut (8)
Sports car in a large Somerset town keeping acceleration at zero (9)
I haven't cracked this one yet — but Fifteensquared have:
A + L (=large, in sizes) + [A (=acceleration, in physics) in FROME (=Somerset town)] + O (=zero, pictorially)
Blackmail material to strike down MP with: corruption involving mother (9)
I haven't cracked this one yet — but Fifteensquared have:
KO (=to strike down, i.e. knock out) + MP + [MA (=mother) in ROT (=corruption)]; from the Russian for “compromising material”, kompromat was used by the NKVD under Stalin to blackmail persons of interest
Mark completed Russian author via audiobook (8)
African fish named in film when caught by sailors (7)
Fighter runs through sobbing person (7)
Info ultimately suppressed had exposed setter's disgrace (6)
I haven't cracked this one yet — but Fifteensquared have:
INF <o> (“ultimately suppressed” means last letter is dropped) + <h> A <d> (“exposed” means external letters are dropped) + MY’S (=setter’s, i.e. Bluejacket’s)
International Baccalaureate excluding overthrown religious leader (5)
I haven't cracked this one yet — but Fifteensquared have:
IB (=International Baccalaureate) + BAR (=excluding, except); “overthrown” indicates vertical reversal
One Barking prison given official documentation (5)
Type letters or click words in the clue