Not done too badly on this one, but with sporadic problems still extant, so some assistance needed.
14A - Having split tea in chair, girl and boy rubbed up the wrong way (9)
I?R???TED
3D Cat, not large, accepted by old province's citizens (9)
N???O?A?S
26A - Truck starts to decelerate, slowly skirting London borough (8)
??A?I???
26D - Heartlessly declare intended challenge (8)
??F?A???
&
36D - First sign of Charlie Brown in uniform - as sort of comic strip? (11)
R?????G????
I hope that assistance with thes will help me do the other ones myself.