I don't have my other HD hooked up right now so I can't actually walk you through this number for number...
However, there are very specifc numbers that stay the same in both the lua scripts and the hex editor. If you open up the scripts in the mod tools for the Dark Trooper, Boba, Jango Fett or for the republic jet-trooper you'll find that they reference specific numbers for the jet-pack.
In my version of Battlefront 2, I increased the jump height for other jet-pack users other than the Dark Trooper. When using the mod tool scripts I usually looked for consistent numbers in the hex editor that correlated exactly to what was listed for that character in the script files.
So if the script for say, the Dark Trooper, has the burn rate followed by the jump distance, followed by the height, you might want to look for those same numbers in the hex editor, other wise it might be a wild goose chase with a lot of trial and error.
It seems like you're on the right path, though. I had a lot of game crashes in BF2 before getting it right.