It may end up being peacful and static, but don't hold your breath.
As always, my opinions arn't worth aren't worth peanuts, but I would guess that greater stress would be placed on keeping all the major cultures within the Imperium (Vilani, Solomani, Sylean, Denebi, Aslan, Vargr, Antares, Daibei, "alien") happy and fed.
There are a LOT of cultures (even a "small" culture can include 10 Billion people, and be in a variety of situations) within the Imperium, and the various competing interest groups may be strengthened vis-a-vis the Iridium Throne and it's Naval and Megacorp backers. Perhaps not democracy, but not the easy ride the Imperium has had since the Civil War (of the 600's, of course).
Of course, I have no problem with the solid, prosperous, boring Imperium of 1105, mainly because I can imagine the amount of work and close calls made to keep the Imperium solid, prosperous and boring for ordinary folk. Every noble must sweat blood trying to keep the peace between systems that could easily rip off each other's faces, and would be pleased to do so if the Imperial Navy would just step aside for a moment....
Hunting down every biowar threat, every pirate holding some tiny world hostage, every attempt to launch a computer virus attack against a space station, every interstellar tourist/terrorist with a small nuclear weapon is exhausting work (and of course, the public simply grumbles about taxes).
AND there is the family politics among the Nobility which get's in the way of needed work (or can suddenly open sealed doors, if you can play it right). Keeping the hundred of thousands of free traders honest is absolutely grinding, and taking on a MegaCorp (or even a sector-wide transport line) is dangerous business, esp. since they can always hire mercenaries and own entire worlds. But the Emperor's Law applies to EVERYONE, someone has got to make even Tukera Lines understand that...
And of course, there is the rare but not unknown possibility that someone slips up, and we get a subsector-wide religious war, the data network over the sector capital collapses, a planetary nuclear war razed the area, or systems need to be put under Martial Law (for harbouring pirates, or attempting to build an illegal Navy to attack the Imperium, or simply being a thorn in the side of the Archduke or some Very Powerful Noble).
Even if the PC's are restricted to the subsector, and can only visit four systems say, you can still get a world of adventure in those four systems. Individual systems live in a near level of total freedom - so long as they don't challange the Emperor or major economic interests. Seeing how all these societies clash and blend is quite interesting in it's own right. Or they may decide to organize (say, unify under a single ruling Count) and try to play the political game for larger stakes. How would this "mini-state" bargain with the subsector Duke for more influence and power is interesting.
If the Referee wants, he can spend several campagins simply on the rise of an insigificant noble family from ruling a large city, to ruling a system, to the Duke and Archduke level, eventually founding a new dynasty on the Iridium throne (doing it right, of course, will take a few generations...).
Just saying that even the "boring", day-to-day affairs of the Third Imperium is quite fascinating in it's own right. It probably won't happen: I would bet that something odd will be going on in the GURPS Imperium...
- who still doesn't speak for Nortel
"His men would follow him anywhere, but only out of curiosity"
- From an Officer Fitness Report, Royal Navy.
All that is gold does not glitter,
Not all those who wander are lost;
The old that is strong does not wither,
Deep roots are not reached by the frost.
- JRR Tolken