What is the best way to create a custom campaign within Thrawn's Revenge?

[Deep Thought]

This is my first post, and I'm very new to forums, so if this needs moved, let me know.

I adore what Corey and the others have done with this mod. Its stunning detail, stability, and forethought stagger me. So much so that I want to tell my own fan fiction style story using their marvelous mod as its platform.

The inspiration for my campaign is in a forum I wrote in that died a little over a year ago before its story could be finished. I'll post a link, but be nice, as the forum maintenance exchanged hands twice after it died out so that it looks truly dilapidated, and none of the formatting has held up.
https://www.tapatalk.com/groups/swtly/#.VfXvMRFVhBd.

I have a story, and I have specific events. That's not my difficulty. My difficulty is I've never created a custom campaign in the ICW Mod, and don't know where to begin. Should I try to duplicate one of the existing campaigns and modify from there? Should I start from scratch? If so, how do I set up a stable choice of planets and starting alignments? Are there ways to test it without constantly loading, closing, and reloading the ICW game?

[Corey]

I did a video tutorial on this a while back:


However, creating an actual storyline for it is quite a bit more complicated.

[Deep Thought]

Its true, I do want to do a storyline, but you provide an excellent starting point Corey. What's more you point out something important. If I want to do a storyline, I should do it after I've built a straightforward GC setup.

I guess this is the point where I bring up the messy stuff. I'm gonna do my best to explain my goals without telling you my life story, but be patient with me if I fail. Here goes:

[Deep Thought]

Ok, so in a way, i recognize my core story is not unlike the New Republic's "Search for Zsinj" Campaign you guys already made. I have some story development scenarios in mind, but ignoring those, its events otherwise play out similarly. I have the major factions splinter into several smaller new ones after a specific major hero (like Zsinj) dies in battle. There's also a diplomacy event not unlike when Leia is sent to Hapes. The difference I have is my "Leia" is a main char who heads to Mandalore with an artifact for a friend: The lost mask of Mandalore 

*Sigh* I guess I really do need to sum up my campaign's story to explain:
It's like this: Year ABY 200 or so, a Deranged Jedi from the Era of Revan awakens from stasis and thinking he's "the chosen one" uses his vast knowledge of the force to take over the Republic. He asserts his will on senators, and even other Jedi using his version of the 'corruption/mind trick' force power to brainwash them, then mobilizes the New republic's fleet along with his own space fleet and armies to make an all-out assault on Bastion, and (in his mind) rid the Galaxy of the Sith once and for all (yea, I could make a campaign out of that, but I'm not). Here's where my campaign begins:

STORY VERSION 1: Empire Faction: The Empire meets the ambush head on and after both sides sustain massive losses, manage to nail the deranged Jedi's fleet and  kill him (they think). With all sides too weak to truly assert their strength over the galaxy, both the Empire and the New Republic splinter into sub-factions and renegade forces, and the Empire attempts to reunify their space and amalgamate the weakened Republic, thus estabishing dominance over the Galaxy.

STORY VERSION 2: New Republic (sorta): You still play the Empire as it defeats the Deranged Jedi, but while this happens, you follow the story of an Echani hero who gets wrapped up in, and watches all this unfold. Minor events happen behind the scenes (Played out at the player's own pace), and the Echani, who happens to hate both Imperial and Republic rule), eventually decides the best way to make ensure neither one is able to stabilize and rule them is to create a brand new faction of star systems eager to rule themselves and not be ruled. Using the mask of Mandalore (which he gains) to unite the Mandalorians and recruit their help, they create a new Alliance .
I'm leaving some big parts out, but faction-wise, that's the goal of what I want to make.)

Now, the first key difference is I have different characters (it being a fan-fiction set long after Paelleon after all). I can actually make use of other characters by changing their Profile .tga images and maybe exchanging some sfx voices. The first question there is can such a transposition be done for just a single campaign, or am I better off just adding brand new hero units?

Second, I expect I will need to tweak some units to fit my anti-establishment alliance, as they will be using mostly racial units, and only a few old ship designs will exist for them to produce. Any ideas how to make this sudden change in available units happen without messing up any factions?

(Sidenote: the icons attached were intended to be visible icons I was going to use in-game. Sadly the site doesn't seem to support img previews for .tga files)