Times 27,251: 28ac was a write-in!
An agreeable middle-of-the-road solve, with a few odd elements that resulted in Minor Eyebrow Raise, but mostly entirely enjoyable. 28ac would have been a rather cryptically labour-intensive clue were it not for the fact that you can write it in from the first half, especially if you happen to be in Berkeley at the time. (Was anyone among our readership solving in or near Morecambe today?) See also 15ac, an interesting surface somewhat marred by the fact that if you don't biff PLUTOCRAT from a 9 letter clue beginning "Cartoon dog..." you're a better man than I am, Gunga Din.
A couple of fairly familiar seeming clue structures (13ac, 26ac, 9dn...) were more than balanced by some much more interesting constructions (14ac, 16ac, 2dn...). COD from me to 12ac because it's a really good word that reminds me somewhat queasily of my college days, nicely cryptically put together. Thanks to the setter for some decent Friday fare. What did the rest of you like or not like? Talk amongst yourselves until we 28-accers finally wake up tomorrow...
ACROSS
1 Insults and criticism for cosmetic (8)
LIPSTICK - LIP [insults] and STICK [criticism]
5 House ending in riot after radical likely to win (3-3)
RED-HOT - HO [house] + {rio}T after RED [radical]
10 Cattle displaying little imagination? (5)
STOCK - double def
11 Additional people arrived to welcome British comedian (9)
MORECAMBE - MORE CAME [additional people | arrived] "to welcome" B [British]
12 Implied backsliding in plan to leave town (9)
RUSTICATE - reversed TACIT [implied] in RUSE [plan]
13 Influence seeing dismissal of foremost performer (5)
ACTOR - {f}ACTOR [influence, "dismissing" its first letter]
14 Sounding nice and posh: no hype, sadly (7)
EUPHONY - (U [=posh] NO HYPE*) ["sadly"]
16 The French taking over from Victor in leading obscure group (6)
LEAGUE - {v->LE}AGUE [obscure, LE "taking over from" V]
18 Set membership fee after rebuffing disagreement (4-2)
BUST-UP - reversed PUT SUB [set | membership fee]
20 Waste surrounding hospital - to what end? (7)
WHITHER - WITHER [waste] surrounding H [hospital]
22 Forced peace-lover to accept war ultimately (5)
DROVE - DOVE [peace-lover] "to accept" {wa}R
23 Something stinking about note in second church melody (9)
PLAINSONG - PONG [something stinking] about LA IN S [note | in | second]
25 Person’s attention given to obsession about Lima (9)
EARTHLING - EAR [attention] given to THING [obsession] about L [Lima]
26 Legal to be guillotined, though dreadful (5)
AWFUL - {l}AWFUL [legal, to be "guillotined" - off with its head!]
27 Expression of enthusiasm about effect of sun in nature study (6)
BOTANY - BOY! [expression of enthusiasm] about TAN [effect of sun]
28 US University: fool recalled another getting one letter wrong (8)
BERKELEY - BERK [fool] + YALE [another (US university), reversed, and with one letter different!]
DOWN
1 One indicates upsetting material about South American prison (5,3)
LASER PEN - reverse REAL [material] about S [South], plus PEN [American prison]
2 Religious minister not coming in earlier (5)
PIOUS - P{rev}IOUS - REV [minister] "not coming in" PREVIOUS [earlier]
3 Be courageous in facing razor blade? (4,2,2,3,4)
TAKE IT ON THE CHIN - an over-literal reading of the phrase meaning "be courageous"
4 Actors wary about start of major review in a negative way (7)
COMPANY - COY [wary] about M{ajor} + PAN [review in a negative way]
6 What’s the point of shouting? (11,4)
EXCLAMATION MARK - cryptic def, the "point" here referring not to an objective but to a punctuation symbol
7 Keen to swamp me with remorse, providing uncomfortable fact (4,5)
HOME TRUTH - HOT [keen] "to swamp" ME, plus RUTH [remorse]
8 Eggs should be going up in your hypothesis (6)
THEORY - ROE [eggs] should be reversed in THY [your]. Isn't a theory famously distinct from a mere hypothesis?
9 Author’s indication of alternative source (6)
ORWELL - OR WELL [indication of alternative | source]
15 Cartoon dog runs into a potential enemy. One could bankroll the movie? (9)
PLUTOCRAT - PLUTO [cartoon dog], plus R [runs] "into" CAT [a potential enemy (of a dog)]
17 Stuffy air around origin of rich friend aiming to save money (8)
FRUGALLY - FUG [stuffy air] "around" R{ich} + ALLY [friend]
19 Spot flag, an excellent example (6)
PIPPIN - PIP PIN [spot | flag]. Not 100% sure how a PIN is a "flag" - Collins has it as "the rod of a golf flag", or maybe we're just talking about some kind of marker?
20 Limits to wider view in dispute (7)
WRANGLE - W{ide}R + ANGLE [view]
21 Clearly providing an example of this (6)
ADVERB - cryptic definition, "clearly" being an example of an adverb
24 Meat product not available? Running short, entirely (5)
OFFAL - OFF [not available] + AL{l} ["running sort", entirely]
A couple of fairly familiar seeming clue structures (13ac, 26ac, 9dn...) were more than balanced by some much more interesting constructions (14ac, 16ac, 2dn...). COD from me to 12ac because it's a really good word that reminds me somewhat queasily of my college days, nicely cryptically put together. Thanks to the setter for some decent Friday fare. What did the rest of you like or not like? Talk amongst yourselves until we 28-accers finally wake up tomorrow...
ACROSS
1 Insults and criticism for cosmetic (8)
LIPSTICK - LIP [insults] and STICK [criticism]
5 House ending in riot after radical likely to win (3-3)
RED-HOT - HO [house] + {rio}T after RED [radical]
10 Cattle displaying little imagination? (5)
STOCK - double def
11 Additional people arrived to welcome British comedian (9)
MORECAMBE - MORE CAME [additional people | arrived] "to welcome" B [British]
12 Implied backsliding in plan to leave town (9)
RUSTICATE - reversed TACIT [implied] in RUSE [plan]
13 Influence seeing dismissal of foremost performer (5)
ACTOR - {f}ACTOR [influence, "dismissing" its first letter]
14 Sounding nice and posh: no hype, sadly (7)
EUPHONY - (U [=posh] NO HYPE*) ["sadly"]
16 The French taking over from Victor in leading obscure group (6)
LEAGUE - {v->LE}AGUE [obscure, LE "taking over from" V]
18 Set membership fee after rebuffing disagreement (4-2)
BUST-UP - reversed PUT SUB [set | membership fee]
20 Waste surrounding hospital - to what end? (7)
WHITHER - WITHER [waste] surrounding H [hospital]
22 Forced peace-lover to accept war ultimately (5)
DROVE - DOVE [peace-lover] "to accept" {wa}R
23 Something stinking about note in second church melody (9)
PLAINSONG - PONG [something stinking] about LA IN S [note | in | second]
25 Person’s attention given to obsession about Lima (9)
EARTHLING - EAR [attention] given to THING [obsession] about L [Lima]
26 Legal to be guillotined, though dreadful (5)
AWFUL - {l}AWFUL [legal, to be "guillotined" - off with its head!]
27 Expression of enthusiasm about effect of sun in nature study (6)
BOTANY - BOY! [expression of enthusiasm] about TAN [effect of sun]
28 US University: fool recalled another getting one letter wrong (8)
BERKELEY - BERK [fool] + YALE [another (US university), reversed, and with one letter different!]
DOWN
1 One indicates upsetting material about South American prison (5,3)
LASER PEN - reverse REAL [material] about S [South], plus PEN [American prison]
2 Religious minister not coming in earlier (5)
PIOUS - P{rev}IOUS - REV [minister] "not coming in" PREVIOUS [earlier]
3 Be courageous in facing razor blade? (4,2,2,3,4)
TAKE IT ON THE CHIN - an over-literal reading of the phrase meaning "be courageous"
4 Actors wary about start of major review in a negative way (7)
COMPANY - COY [wary] about M{ajor} + PAN [review in a negative way]
6 What’s the point of shouting? (11,4)
EXCLAMATION MARK - cryptic def, the "point" here referring not to an objective but to a punctuation symbol
7 Keen to swamp me with remorse, providing uncomfortable fact (4,5)
HOME TRUTH - HOT [keen] "to swamp" ME, plus RUTH [remorse]
8 Eggs should be going up in your hypothesis (6)
THEORY - ROE [eggs] should be reversed in THY [your]. Isn't a theory famously distinct from a mere hypothesis?
9 Author’s indication of alternative source (6)
ORWELL - OR WELL [indication of alternative | source]
15 Cartoon dog runs into a potential enemy. One could bankroll the movie? (9)
PLUTOCRAT - PLUTO [cartoon dog], plus R [runs] "into" CAT [a potential enemy (of a dog)]
17 Stuffy air around origin of rich friend aiming to save money (8)
FRUGALLY - FUG [stuffy air] "around" R{ich} + ALLY [friend]
19 Spot flag, an excellent example (6)
PIPPIN - PIP PIN [spot | flag]. Not 100% sure how a PIN is a "flag" - Collins has it as "the rod of a golf flag", or maybe we're just talking about some kind of marker?
20 Limits to wider view in dispute (7)
WRANGLE - W{ide}R + ANGLE [view]
21 Clearly providing an example of this (6)
ADVERB - cryptic definition, "clearly" being an example of an adverb
24 Meat product not available? Running short, entirely (5)
OFFAL - OFF [not available] + AL{l} ["running sort", entirely]