Well, with storyboards done and animatic planned I’m not sure I’m not too late to take you back to the story itself but here’s my two bits.
The key scenes are going to be the first one and the last one: the setup and the epilogue, these are the two scenes which are the story. The rest of the scenes are really the path that the character takes and it looks like it will be a winding, wild path full of gags. Still, I think to make the film something more than a series of gags, it wouldn’t take much work.
First, we (the audience) have to know why he got into the plane and decided to jump: was it just for a thrill, was he looking for more in life, did he just do it without much forethought? The first scene really suggests that he has done it before, he likes it enough to do again and is feeling pretty confident that he’s going to have another excellent experience. Maybe he is extremely experienced, the penultimate expert at skydiving or maybe just expert enough to feel cocky. Maybe he’s just had an unfortunate experience at work or home and this is his way to leave all his troubles behind even if it’s only for a few minutes. Either way, I suggest we introduce that he’s got something to prove to himself or someone else with this jump. This jump means something to him.
At the end, he has to be thinking about skydiving in a whole new light. The experience has to have changed his outlook in some reasonable but unexpected way. The cocky or expert skydiver will be reminded of their mortality, the cocky one being scared off skydiving forever but the expert being wiser but still determined to jump again. Maybe the character who wanted to leave all his troubles behind finds out that his troubles follow him, or that having triumphantly survived a disastrous fall intact has the fortitude to face his difficulties.
You want to suggest that there is more to this guy’s world than just this jump and you want to add some aspects to his character that the audience can identify and connect with. “There but for the grace of god, go I!” is what the audience should think.
Our character (our because we need to identify with him) can start off happy/sad, mad/ peaceful, confident/scared or any combination of those. Personally I think contradicting feelings makes it more interesting: happy and scared, confident but sad.
Then in the end the character can either be alive or dead, battered or whole, but with a transformation in his original feelings from the start of the movie: from mad to happy, from sad to mad, from scared to confident.
I personally prefer the battered but wiser kind of ending myself.
Along the way, the things the skydiver encounters change his moods, moving him through these various emotions–happy, scared, confident, sad, peaceful etc.–possibly each change being an extreme change rather than a gradual one: happy to mad, mad to peaceful, peaceful to scared, scared to happy…
Hope that helps, although perhaps is complicates what was mearly supposed to be a gag reel… 
Peter
.