Jacob Two-Two meets Schrödinger's letter

Answer: BACKSPACE


Each pair of clues yield (sometimes silly) phrases that differ only slightly: one letter is in a superposition and can't decide whether to be the last letter of the first word or the first letter of the second word:

Clue 1Answer 1Clue 2Answer 2Letter in superposition
Exceptional birdSUPERB OWLChampionship sports gameSUPER BOWLB
Poetry about a large brass instrumentTUBA VERSEDisliking of bathsTUB AVERSEA
3.26 lightyears oldPARSEC AGEAnalyze the grammar of a pet rodent's homePARSE CAGEC
Rebellious electrified water-dwellerPUNK EELStabilizing component of a joke-telling boatPUN KEELK
Spicy dish in support of freedomsRIGHTS CURRYA quick move away from something on your leftRIGHT SCURRYS
Well-fed noblePLUMP EARLPurple coloured jewel from the seaPLUM PEARLP
Performance enhancing drug used in the Capitol BuildingROTUNDA STEROIDPortly solar system objectROTUND ASTEROIDA
Supernatural chess pieceMAGIC ROOKBiblically wise con artistMAGI CROOKC
Diet version of a martial artKARATE LITETop-class metallurgical purity puristKARAT ELITEE

These letters in superposition spell the answer BACKSPACE.