Those in the know suggested this was at the easy end of The Listener scale, so I thought I'd give it a go. I've managed to finish it (I think!), but the parsing for this still eludes me....
14d. As with McEwans beer from the south, not entirely promising (6) - LIKELY
If I've got this right, the wordplay should lead to 7 or possibly 8 (the 'not entirely' might indicate a contraction) letters. The extra letter (or one of them) is an 'I'. I think 'As' might be 'Like', but that's as far as I get. Help appreciated.