26ac: Rugby conservative? (3,6)

Yet another demonstration of why DA is a master. The answer here is old school, expertly combining some slang originally from the USA with a nice piece of sporting trivia.

4dn: The smart set up commonest Scrabble piece (5)

Scrabble and a cryptic clue combined — could there be a finer logophilic combination? The E tile is the commonest in Scrabble, and when you read that backwards, you get elite.