9 Stop love ring being forbidden. (5) (TABOO) TAB is a stop (as in typesetting), both love (think tennis) and ring are O. TAB+O+O makes TABOO, which means forbidden.
10 Pompous Ed dancing with Signora. (9) (GRANDIOSE) Anagram of ED and SIGNORA, signalled by the word dancing, to make GRANDIOSE, which means pompous.
11 Managed her voting from one day to the next. (9) (OVERNIGHT) Anagram of HER VOTING, signalled by the word managed, to make OVERNIGHT, which is clued by from one day to the next.
12 Note one artist has crown. (5) (TIARA) TI is a note (in do, re, mi, etc), A is one, and RA is artist (member of Royal Academy, standard crossword abbr.) making TI+A+RA = TIARA, clued by crown.
13 Firm friends. (3) (SET) Double meaning, both words can be synonyms of SET.
14 Did blond elf stray with eyes covered? (11) (BLINDFOLDED) Anagram of DID BLOND ELF signalled by the word stray and clued by with eyes covered.
16 In church, getting home before midnight but moving very slowly. (7) (INCHING) Series of short, simple definitions: IN (in) + CH (church) + IN (home, as in at home) + G (midnight, as in middle letter if night) to make INCHING, clued by moving very slowly.
19 Oddly verbose witness. (7) (OBSERVE) Anagram of VERBOSE, signalled by oddly to make OBSERVE, defined by witness.
20 Lady killers? (11) (MURDERESSES) Simple pun; the clue implies the killers kill ladies but these killers are ladies.
22 Gulp back yellow, oozing substance. (3) (PUS) Reverse (signalled by back) of SUP, clued by gulp, to give PUS, defined as yellow, oozing substance.
23 Change element at the start of 28; relates to the other end of life? (5) (NATAL) Replace F with N on FATAL, which is the answer to 28a. F and N are both elements. Fatal refers to the end of one’s life, whereas natal refers to the start.
24 Teamwork as Italian football team have a game. (9) (INTERPLAY) Sequence of definitions: INTER (for Inter Milan, clued by Italian football team) + PLAY (clued by have a game) to give INTERPLAY, defined by teamwork.
27 See Eastern boy in records about affairs of the heart. (4,5) (LOVESONGS) Sequence V (see) + E (eastern) + SON (boy) gives VESON. Pop that inside LOGS (records) to get LO+VESON+GS, or LOVESONGS, clued by records about affairs of the heart. Note records is reused for two components of the clue.
28 Chubby mobster is deadly. (5) (FATAL) Sequence of definitions: FAT (chubby) + AL (mobster, for Al Capone) to give FATAL, defined by deadly.
1 Either way, he’s the Holy Roman Emperor. (4) (OTTO) Holy Roman Emperor whose name is a palindrome (either way).
2 Amateur corrupt, having shilling missing. (6) (ABSENT) Built from A (absent) + BENT (corrupt) containing S (shilling) to give ABSETm clued by missing.
3 Rub shoulders with biscuit? (6) (HOBNOB) Simple pun; a HOBNOB is a type of biscuit and can also mean to associate with or rub shoulders with.
4 Yoruba bell, nothing missing, is struck. (4) (AGOG) Subtract the letter O (nothing missing) from AGOGO (a Yoruba bell) to get AGOG, clued by struck.
5 Summary proof of age promises to be discriminatory. (10) (FASTIDIOUS) Sequence of definitions: FAST (summary, as in summary execution) + ID (proof of age) + IOUS (promises, as in I.O.U.s) to give FASTIDIOUS, clued by discriminatory, in the sense of discerning.
6 Alter charged particles for print runs. (8) (EDITIONS) Sequence of definitions: EDIT (alter) + IONS (charged particles) to give EDITIONS, clued by print runs.
7 Programmer has local network that’s full of holes? (8) (COLANDER) Container: CODER (programmer) contains LAN (local network) to give COLANDER, clued by that’s full of holes.
8 Without esteem, anyway. (10) (REGARDLESS) Simple pun: REGARD + LESS sounds like it could mean having no esteem; clued by anyway.
13 One at a time to hold Mayfair maidens with no trouble. (10) (SWIMMINGLY) Container: SINGLY (one at a time) contains WI (Mayfair, postcode W1) and MM (maidens, from the cricket abbreviation m. for maiden over) to make SWIMMINGLY, clued by with no trouble.
15 Factor in gender, it’s crazy. (10) (INGREDIENT) Anagram of INGENDERIT (in gender it) indicated by crazy and clued by factor.
17 Remedial coward Evita put up. (8) (CURATIVE) Sequence of CUR (coward) and ATIVE (Evita put up, i.e. evita backwards) makes CURATIVE, clued by remedial.
18 Romantic concept menu. (8) (IDEALIST) Sequence of IDEA (concept) and LIST (menu) makes IDEALIST, clued by romantic.
21 Untidy fellow put up with having credit without hesitation. (6) (SCRUFF) Built from SUFFER (put up with) minus ER (without hesitation, i.e. missing er) to give SUFF, which then contains CR (having credit) to give SCRUFF, clued by untidy fellow.
22 Well-mannered European has sex appeal. (6) (POLITE) Container: POLE (European) contains IT (has sex appeal) to give POLITE, clued by well-mannered.
25 St Vitus kept tooth hidden inside. (4) (TUSK) The words hidden inside indicate that a word for tooth is hidden in the clue: St Vitus kept, contains the word TUSK.
26 Vitellus: originally Yorkshire’s oldest lime kiln. (4) (YOLK) The word originally indicates using the first letter of each word, and the first letters of Yorkshire’s oldest lime kiln give YOLK, clued by vitellus.