Star Wars Rebellion modding Thread

Hello:)

First at all i`m a modding rookie. Never tried this (most of all it was texture swap and stuff like this.)
I wanna to try make a mod to STAR WARS REBELLION (`98)
First idea was to create new campaign, with new ships and units and maybe speeding up ship fight, making it more intense.
Second idea... How about toogling "time". (In normal SW:R we start soon after destruction of Death Star), so i imagined that we could jump through campaigns in one game instead launching different versions- Main menu changes a bit.
Third idea... Rebellion is almost not known it would be nice to re- introduce star wars fans community with it. But most of younger players are thinking: "What a dumb graphics? WTF is this?! A game for calculator?, etc"

So answering a few questions before they appear... Yes i have considered modding SW: Empire at War, but i think that code from Rebellion would be kinda easier, more primitive- better for a rookie.
I am quite familiar with modeling, texturing (hate this...), and animation.

And yes question from me:
Is this even possible what i imagined?
And if yes then with what can i decompile files?
I hope that all of this will not end with "Create New Game. Easier and simpler in this case."

Thanks.