Totally baffled by the final clue:-
Alter the course of a Slavic person? (4)
I have *E*D
The E is the first letter of ELECT, the clue for which was "The chosen choose. (5)".
The D is the first letter of DEADEND, the clue for which was "Could Dad need labyrinthine cul-de-sac? (4,3)".