I saw the next campaign you're going to be doing is Burning Heaven. That has multiple endings. I'll give you some advice on how to get the best ending for that campaign if you want to (marked for spoilers of course). Some missions you don't really have any moral choices to make and can just play normally and some missions you have to make certain decisions in to get the best ending for the campaign. I've marked as spoilers the general mission description even if there are no decisions to make.
There are nine possible missions total in BH.
M1
This is largely just a playable intro cutscene and no moral decisions to make.
M2
Protecting a colonial ship from Earth attack
No decisions to make, you can play straight through.
M3
Protecting surrendering colonials from Earth reprisals.
Decision:
There are two fellow pilots you can save by flying next to them and the game will have you dock with them and save them. The mission has you do one automatically but you have to save the second one at the end to get the 'best' ending. FYI though, if you don't save the second one you can still get a 'good' ending, but saving both will make the final mission briefing a little bit better.
M4
Attacking Earth comms ship "Constantine"
Decision:
After you hijack the Earth transport in the beginning of the mission, you have the choice on whether to leave or kill its escort. I don't actually know for 100% if this decision affects the ending, but I would advise leaving them and not killing the escort to get the best ending. That's what I've done at least.
M5
Sabotaging the Nero
This is the big one. You don't even get to play mission 9 and you get the bad ending if you make the 'wrong' decision here.
Decision:
You have a choice at the end of the mission to detonate a bomb on the Nero when it's next to a large civilian transport. DO NOT send the detonation message...DO NOT destroy the Nero here if you want the best (or even good) ending.
M6
Earth attack on Titan
No decisions to make here, play straight through.
M7
Escaping Earth attack in gas/nebula environment
No decisions to make here, play straight through.
M8
Hacking Earth comms station
No decisions to make here, play straight through.
M9 (In the bad ending path, you don't get to play this mission and the campaign ends with M8)
Attacking the emperor on his flagship Phalanx
I would argue this is the second most important decision you can make in the campaign if you want the 'best' ending.
Decision:
At one point one of the enemy destroyers tries to surrender but radicals try to keep fighting...the CO of that ship asks for more time for he and the loyalists to take control of the ship and surrender. You are given the option to destroy that ship. To get the best ending do not destroy that ship...tell your forces to ignore it and eventually the CO gains control and completes the surrender. This will prompt the Phalanx to surrender too. You are praised for your morality in the debriefing.
