Lovatts colossus 124, Giant Cryptic

Can't help with 22a but, apart from that, I think you may have an error or two. My suggestions (in BOLD) for the rest are:

1a Setting out with title stripped (7,3) s?a???g ?f? HEADING OFF - check that "s"!
20a Speak indistinctly after knocking back one rum after another d?r??? MURMUR - check the "d"!
26a Intend to make expert accept stance (7) ?r?p??? PROPOSE
7d Be passionate about Shine (6) l?s??? LUSTRE
14d a tense time ahead (6) ?a???e FUTURE - check the "a"!

Hope that helps. Good luck!

Thanks Imur those answers helped a lot really appreciate your help.

Hi Jeans.

Agree with Lmur's submissions.

22a = GROOVE

Good luck.