So I am running my Only war campaign soon and was looking for some Ideas.

Here is what I have so far, Players start off at Port Wander. I had each player make a backround for their character and how they joined the crew.

-Rogue trader- a cadian born noble who Inherited the warrant of trade after service in the imperial Navy. the rogue trader is a pious man but not opposed to dealing with who he needs to deal with in order to get the job done.

-Ork (hed of sekurity)- during a lengthy fight in which the rogue trader's ship destroyed an ork cruiser the ork character was thown out into space (in a voidsuit) and hit the Rogue trader's ship. he then crawled to an airlock and made his way into the ship. the rogue trader saw some use for an ork and offered them a job.

-Arch militant- an imperial fugitive who became a stowaway on board the ship. he took a crew member hostage when discovered by the rogue trader and demanded that the rogue trader drop him off on a nearby planet. The rogue trader admired the resourcefulness of the man and offered him a job in exchange for "not pulling that **** again."

-Void Mistress- a noble born member of the ship and it's primary pilot (though other members are qualified). She was hired by the rogue trader at some point in the past (though the rest is unknown).

- Possibly two others who haven't made a character yet most likely will be a navigator and an explorator.

What I need are suggestions for various scenarios, this campaign will largely be made up of the players deciding where they want to go in the galaxy and I want to make sure I have stuff for them to do or rumors of something going on in various places. (example: rumors of a Genestealer cult on one planet or tales of a space hulk filled with riches).

I have some plans that I will include including one pissed off rogue trader that is hunting down the PCs but I need more ideas besides what is in the books.

Profitable rumours:

1. The Mass Conveyor Swift Tide - a Gigafreighter operated by one of the Rogue Trader's rivals - struck a warp riptide and foundered. She made it to a nearby uninhabited system, and the rival dynasty is trying to repair her - constructing a makeshift drydock and trying to render her warp-worthy; either to complete its journey or to reach a proper shipyard like Damaris or the Breaking Yards. The ship is laden with a massive quantity of high-grade starship fuel which the dynasty has sold to the Koronus Passage Watch squadron. If it doesn't arrive, your rivals will suffer a loss of face with the Navy, have to pay massive reparations (in addition to the loss of the Swift Tide itself). Not to mention that you might be able to steal the cargo and sell it elsewhere in the expanse - or help boost your own reputation with the navy by 'making up the shortfall' yourself with the stolen promethium....
2. An ecclesiarchal missionary is seeking aid; a small pilgrim colony on Saint Iacton's Hope has been occupied by pirates who are using the system as a base - forcing the colonists to grow food for them, pressing the population into service on the handful of wolf-pack raiders they operate out of the system, and generally oppressing and abusing the population as well as striking out from the system against nearby trading ships. The populace are poorly armed (being those pious sorts who took the Decree Passive seriously), and although there are about a million colonists, they have no real choice but to obey - the pirates are well armed and if any part of the settlement gets too uppity, the pirates can just shell it from orbit with macrobattery fire. Liberate the colony - and provide it with some permanent defences - and both the colonists and the Ecclesiarchy at large will owe you a favour
3. An ork raider has been attacking Imperial shipping near the Cursus system. This ship has a bounty placed on its head by several dynasties but the Orky Kaptin is dead kunnin' and no-one's been able to catch him yet with any ship large enough to beat him when he's done so. Perhaps the Hed of Sekurity and the Rogue Trader can, between them, lure him into a trap?
4. A mysterious patron named Master Nonesuch wants you to acquire a set of artefacts - mostly from uninhabited worlds in the expanse rumoured to hold dead Yu'Vath outposts, but one that's already been found by an archeological expedition by a different dynasty. He can provide (suspiciously) exacting detail on the artefacts and their locations, but acquiring them (and getting past any surviving Yu'Vath automated defences) is your problem. He almost certainly wants them for no good reason but is offering a staggering amount of thrones in payment - even to a Rogue Trader.
5. In order to maintain a solid lifeline for trade, supplies,and other logistics, the Dynasty needs to establish a meaningful stronghold at both ends of the Maw. On Port Wander, this is easy - polite diplomatic negotiations, and a discrete flash of an Imperial Warrant of Trade, and a spire-deck manse can easily be leased. Acquiring meaningful secure real estate on Footfall is somewhat harder, and generally involves evicting the current occupants. Violently.
6. One of the best ways to establish a reputation is 'big game hunting' and the Expanse has no shortage of alpha predators deserving a spot on the trophy wall.