My players first adventure will be as a favor to the High Lords of Terra before they go out into the unknown. In the Calixis Sector is the Duronia system. The government of Duronia IV has not paid their full tithe in years and none at all in recent years. They are to go discuss things with the Imperial Governor, find out the reason for the issue, and get a written promise that the next tithe will be paid in full. Just send a psychic impression of the document to the Calixis capital to be sent on to Terra.
On the way in, they'll meet pirates. Later learning this is the reason for the tithe issues as pirates have all but blockaded the system while moving out of the way when officials come to collect.
They are asked to bring the pirates down and that they base themselves out of an old station above Duranis V. This turns out to be a trap.
Once they survive this and meet with the Governor again, it is revealed by a source that the Governor dislikes this world and wants to conquer another more prosperous world "in the name of the Emperor". He plans to frame another world for treason and kill them for it. To this end, he is controlling the pirates and has a real base on Duranis III, a former Forge World. If the Governor escapes the pcs, he flees here where the pirates have taken valuables, materials, and manpower so the Governor can build himself a crusade force. If they kill the Governor, this secret base offers no conflict. The players are rewarded and they go about their business. If the Governor escapes, there's a vicious battle that only lasts until the Governor is killed. Once he is dead, the others surrender and reward the players. The Governor doesn't play with Chaos or anything. He's just greedy and ambitious (and murderous as he had the previous Governor killed so he could take control and declare himself in charge with martial law in place since before being Governor he was the Commander of the local PDF)
At some point, this Governor does offer the players a role in his growing military and places of power on his new world that he intends to conquer. Mostly at that point, he just wants to not be killed, but also would like the players who could defeat him to help him instead of hurt his ambitions.