Okay then, here goes your starter for ten.
OG5:1
Opening seequence - flashback to Kabaul in the moments before the explosion, re-edited to show GL being vuried in debris after a different explosion.
Cut to GL in hospital bed, unconscious.
Pull out to show members of 2 Section round her bed, talking about what went on in Nigeria (but without her in it), Bones included fade ...
fade up to other members of 2 Section round her bed, talking about Belize, Bones included, and CJ injury included, GL not included fade ...
fade up to ditto, talking about Bangladesh, Bones included (but not exploded), CJ included, beardless Spanner, new SF boss included. When telling GL about it reaches the end of 4:8, CJ's voice says 'ten paces back' or something which sounds like that, and 2 Section members move out of shot while another figure moves into shot in silhouette and somehow, clumsily, manages to knock tumbler / jug / bottle of water over GL ...
Cue titles
Cue fuzzy brightness and sound. Slowly brightness dims and takes blurry shape which turns into an indistinct, out-of-focus face; the sound becomes a distorted voice, as if from a distance. It seems to be saying something. Slowly, the sound takes the shape of words, "I'm sorry, George ...' said again and again.
Cut to GL, blinking,
Blah, blah, blah.
The point being, she's been unconscious / in a coma and everything that happened in the last series and about the last 20 minutes of OG3:4 is GL's mind making some sort of distorted sense of what 2 Section have been talking about when they came to visit.
Elvis did go to do selection at Hereford (did he fail Fingers?). GL already knew Bones - he tells her he liked Elvis, so there's a chance that GL may have met him as one of E's mates. CJ could still have had the accident in Belize, which allows Bones to take over in Bangladesh, but he doesn't have to get blown up. That could be GL mishearing something in her comatose state.
Could still have the new SF guy too, as Bones is shipped home for whatever reason and CJ returns.
So, thus having got rid of the worst bits of OG4, we are all set up for OG 5, without the CJ/GL thing, with Elvis back in Hereford (and able, like GL's ghastly mother, Molly, Kingy's family and Monk's girlfriend) to text, phone and skype. We could still have s/one (other than CJ) trying it on with GL, either because he doesn't know about Elvis, or because Elvis is in Hereford ...
We could have UK-based stuff, whether home or barracks, and explore the PTSD angle.
Over to the rest of you, ladies.