1: Sounds like a bright child (3).
2: Importance of history (7)
3: He is round (grossly fed) (9)
4: Farm animals put on islands (7)
5: Sissy's fabric cleaner suggested by the Rev. Spooner (7)
7: A representative may be a scamp (3)
8: Employ heart-broken Spartans where disaster came to pass. (11)
11: Stimulant produced as choir paid off (11)
13: Child, bask by the sound (3)
16: Face facts, Sir? .... Act! Lie! Lead Astray! (9)
18: You audibly ram partner (3)
19: The near-breaking of ground (7)
20: Injured girl with sword. (7)
21: Assembly said Dracula's sick (7)
23: Yes. No. Maybe. Getting personal (5)
26: Crew member is one in operating room (3)
28: About....about right? Wrong! (3)