I have to agree. I know cryptic is cryptic, but some of those clues had to be among the most tenuous ever. "Parroted" is a case in point . . . Polled? Polly parrot? Nah.
SC is South Carolina - exercise is PE, as you suspected.
You are correct - the clue Polled - to give answer Parroted is absolutley rubbish. I think that they must have either got a new compiler or are getting too many correct submissions.
Simple solution - do not buy the Telegraph! To call the mountain clue crap when it is perfectly acceptable is a nonsense - Mountains (Urals) stopping short (-s) of southern river (Ural). Ok parroted IS a little tenuous but Chambers has poll-parrot as a verb meaning to parrot so it isn't beyond the realms of possibility that some dictionaries have shortened poll-parrot to poll which would make the clue quite satisfactory.