ACROSS
9 Sons urge to get Transformers? (7,8) PLASTIC SURGEONS {SONS+URGE}* [RA]
10 English politician's mistake disheartened king (7) EMPEROR {E}{MP}{ERrOR}
11 Study of animals around Australian's old timber yard (7) ZOOLOGY {OZ<=}{O}{LOG}{Y}
12 Nut-free oat chips - Have one? (9) PISTACHIO {OAT+CHIPS}* over {1}
17 Mother's reading Thai novel in another language (7) MARATHI {MA}{R}{THAI*}
19 Regularly referred by her blogs, find about rebel (7) DISOBEY {bY+hEr+BlOgS+fInD}<=
21 Ditch tailor (5) SEWER [DD]
23 Collapse after uncontrolled rapid rise (9) DISREPAIR*
30 Find lifestyle changes involving criminal - one escaping coolly (4-11) SELF-CONFIDENTLY {FiND+LIFESTYLE} over {CON}
DOWN
1 Lamps seen periodically in part of church (4) APSE {lAmPs+SeEn}
4 My school's covering what a singer can do! (6) SCORCH {S{COR}CH}
5 Catchphrase or term in Spelling Bee? (4,4) BUZZ WORD [DD]
6 Take no notice of flower on girl - some rose (6) IGNORE [T<=]
7 Fast food in two seconds (4) MOMO {MO}{MO}
12 Draws little dogs cuddling master (5) PUMPS {PU{M}PS}
13 Yellow and green under stone (5) STRAW {RAW}<=>{ST}
18 At home, work fast and slow (8) INDOLENT {IN}{DO}{LENT}
20 Spice used by 50% of people, for example (8) SPECIMEN {SPICE*}{MEN}
22 Second veto (6) REJECT [DD]
24 Pursue victory, we hear it makes one shine (6) SEQUIN (~ seek win)
25 Extra towel initially removed from hamper to sunbathe (4) BASK BASKet
26 Lazy hero gets picked up (4) IDLE (~idol)
28 Has leader lost from constituencies (4) EATS sEATS
29 Dark sauce containing egg's cooked, say (4) SOYA {O} in {SAY}*
Reference List
English = E, Old = O, Yard = Y, Reading = R, New = N, My! = COR, School = SCH, Second = MO, Master = M, Stone = ST, At home = IN