Across
Humorous, it comes to screen – the full-length version? (9,6)
I haven't cracked this one yet — but Fifteensquared have:
‘ sitcom ‘, the not-full-length version, can be found in [Humourou]- S IT COM -[es] “screen” meaning to conceal or hide, indicating hidden words
Calculations appear to be switched for theologian and scholar (7)
I haven't cracked this one yet — but Fifteensquared have:
Erasmus the Dutch theologian [wiki] SUMS ARE=”Calculations appear”, reversed/”to be switched”
Payment to central government fund went on courses for the auditor? (4,3)
12a
What connects 9, 13, 15, 20 and 28, after which number comes down (3,11)
See 11
Isle found east of a geographical region, as explorer (4,6)
I haven't cracked this one yet — but Fifteensquared have:
Abel Tasman the Dutch explorer [wiki] MAN (Isle of Man); to the right/east of A BELT AS=”a geographical region, as”
Artist applauds: I will be thrown out (4)
Eccentric, however you look at it (4)
I haven't cracked this one yet — but Fifteensquared have:
“however you look at it” (i.e. whether you read it backwards or forwards) indicates a palindrome
Reportedly offensive winger, Italian footballer (4,6)
What 9, 13, 15, 20 or 28 might say that's highly unlikely! (2,1,8)
King and Queen feast outside? (3)
I haven't cracked this one yet — but Fifteensquared have:
the singer B.B. King [wiki] ; plus Q (Queen, chess notation)
First of errors by steeplejack's ending in inaccurate inspection (4-3)
I haven't cracked this one yet — but Fifteensquared have:
first letter of E-[rrors], next to: LOOSE=”inaccurate” around the ending of [steeplejac]-K
Blockbuster film cut a magical character (7)
Nation's father is bound to go far with one aim for reform (7,2,6)
I haven't cracked this one yet — but Fifteensquared have:
William the Silent [wiki] led the Dutch revolt against the Spanish Habsburgs (…not the William of Orange who was William III of England) WILL=”is bound to” + anagram/”reform” of (go far one aim)*
Down
Little time in hunt for blandishments (5,4)
Flier's rôle, swinging up with lack of effort, say? (7)
Fossil, a little one with day inscribed (8)
I haven't cracked this one yet — but Fifteensquared have:
A MITE=”a little one”; with MON (Monday) inside
Page within a page, it's entangled? (5)
I haven't cracked this one yet — but Fifteensquared have:
“it’s entangled” to be read as ‘it’s en… …tangled’, so anagram/”tangled” of (it’s en)*
Danseur: I'm remarkably tender (9)
Sage or coriander originally in brew (6)
I haven't cracked this one yet — but Fifteensquared have:
OR (from surface), plus C-[oriander] inside ALE=”brew”
Land, not sea, I gathered (7)
Line going up, boundary always vertical (1-4)
I haven't cracked this one yet — but Fifteensquared have:
SIX=”boundary” (scoring six runs in cricket with a shot over the boundary of the field) + AY=”always”; all reversed/”vertical”
Short root, large amount that's often served with nachos (4,5)
Triangular item assigned shape (3,6)
Cheese turns me off, tiniest piece of Edam eaten ... (8)
I haven't cracked this one yet — but Fifteensquared have:
anagram/”off” of (turns me)*; around/eating a piece of E-[dam]
... where cheese may be cooking (2,1,4)
I haven't cracked this one yet — but Fifteensquared have:
I think the definition is “cooking” as in ‘progressing’, ‘happening’ (e.g. ‘what’s cooking?’) cheese may be ON A [bread] ROLL
Force blockading British country (7)
I haven't cracked this one yet — but Fifteensquared have:
LEAN ON=put pressure on [someone]=”Force”; around B (British)
Greek character lies about item on breakfast menu? (6)
I haven't cracked this one yet — but Fifteensquared have:
MU=letter of Greek alphabet=”Greek character” + anagram/”about” of (lies)*
Relative where one finds Hollywood wife (2-3)
I haven't cracked this one yet — but Fifteensquared have:
one finds Hollywood IN LA (in Los Angeles); plus W (wife)
Legal requirement with 10 providing theme (5)
Type letters or click words in the clue