Having a 100 mission campaign as a first project is the way to failure, frustration and quitting.
To add to the above statement, Procyon Insurgency which is considered one of the best mods out there, had (supposedly, don't remember where I read it) testing period consisting of no less than fifty playthroughs. For
each mission. Assuming ten minutes per mission, that's one hundred and ten hours just to test the thirteen mission campaign. For your campaign that would add to over eight hundred hours (thirty five days of continuous play).
Or let's look at another example. Blue Planet is one of the best, most polished mods out there, but it's still full of things the devs simply did not anticipate or didn't think about. For example, in one mission it's possible to save a certain ship (Vilnius), many people have done it, but the game never acknowledges it and plays as if the ship was destroyed. In another mission I managed to disable a corvette that was supposed to jump out, which made the vessel invulnerable and ended up breaking pathing of an allied ship, making me fail a mission. And that's in a mod that currently has thirty or so missions and has been in development for years. By a whole t
eam of people no less.
I'm not saying what you're attempting is impossible, but if you have only yourself to test the game it's very likely the players will end up breaking up missions by doing things you never thought of by yourself. That's why testing is usually done my multiple people, some of which are even brought outside of the dev team.
And I'm not even addressing the fact that using retail assets (both the retail exe and retail-grade assets) will certainly not help to get people to play your mod.
It may not make people play your mod at the beginning, but I wouldn't worry about that in the long run. If the mod itself is good, people will play it, even if it uses retail-grade assets. I don't know about other people, but The Derelict is one of my favorite mods despite it's age.