Yes, that is true those starbases didn't move... but the Death Star did. We don't know how large the starports are in this game vs. the size of the starbaes. It could be that starbases are 100 times larger than a starport. Hence impractical to move starbases but not starports.
You've got me on the Death Star. I guess I just personally like my space stations staying put.
Personally, I do not consider the Death Star to be a space station. Its intended purpose means that it had to have been intended from the start to be a mobile craft, and it wasn't exactly something meant to be left in one place very long; its very existence and its ability to reach a target in a relatively short time frame should have been a sufficient threat for the intended purpose without requiring it to be constantly orbiting a given trouble spot, and making it immobile would have defeated the purpose. Rather, I would consider it, and especially the second Death Star, to be a kind of super-heavy capital ship, or perhaps a mobile super-heavy siege weapon with significant self-defense capabilities, but not a space station despite it having been described as such within the movies.
The few things we do know is, that it would take 10 years to travel via stargate from Earth to Arcea, and that it took the Drengin 70,000 years to ferry their stargate to Toria (which is 20 light-years away from Drengi).
Under a constant-acceleration model, the stargate's acceleration is only 7.755X10^-8 m/s/s, while under a constant-speed model the stargate's speed is 85,655 m/s (~0.00029c) for the Drengi-Toria journey. If the stargate's journey were representative of the capabilities of sublight drive at the time, then under the constant-speed model the 10 million mile trip takes a little over two days, while under the constant-acceleration model it takes a little over 3700 days (~10.2 years). While I'd expect that the actual travel time figures would be considerably closer to the lower bound than the upper bound, we simply do not have the information necessary to establish how close it is to either bound; the Earth-Arcea travel time is even less useful in establishing this since we don't know the distances involved or the path issues involved.
We can estimate the distances using the Drengi-Toria stargate travel time, which would put Earth ~114.3 light-years from Arcea by the constant-speed model or about 653 light-years from Arcea using the constant-acceleration model, if a probe had been launched from Arcea directly at Earth at the '400,000 years ago' mark in the timeline in the databanks and had exactly the same speed/acceleration as the stargate launched by the Drengin at Toria, but it's unlikely that the Arcean probe would have taken a direct route to Earth from Arcea and so Earth could be considerably closer than either estimate would indicate.
We alternatively know that it took the Drengin approximately 250,000 years for one of their probes to visit a star within 20 lightyears of their own; if we assume that the probes sent out by the Drengin and Arceans are capable of the same performance and that this is the time taken for the probes to completely survey a sphere centered on the homeworld with a radius of 20 lightyears, then the probes are capable of surveying about 0.1 cubic light-years of space per year; if this rate of exploration continues until Earth is found, then Earth is within about 23.4 light-years of Arcea. Using this last estimation model, we can also predict that Arcea and Drengi are separated by about 14.7 light-years. This last estimation model is of course somewhat lacking, as in all likelihood the Drengin and Arcean nations had determined a set of stars which they considered to be more worthy of investigation than others, or, better, a set of parameters allowing the probes to prioritize visiting certain types of stars before others, based on their theories of planetary formation and their expectations of the probability of life emerging on such worlds, rather than the blind exploration assumed by the model, and, as with present-day astronomy, the Arcean and Drengin astronomers may have identified stars where worlds were known to exist prior to sending out any probes whatsoever. It is nevertheless a more reasonable distance estimate than either the constant-acceleration or the constant-speed model for determining the distance between Earth and Arcea (unless you're trying to establish the total distance traveled by the Arcean probe which first reached Earth, which could perhaps have traveled the roughly 115 light-years estimated by the constant-speed model if it had been bouncing around from star to star on its journey, though the constant-speed model has its own issues, such as not necessarily accurately reflecting the average speed of the Arcean probes; certainly the probes are unlikely to follow the constant-acceleration model developed from the known performance of the stargate's journey).
I would also point out that there are some indications in the Databank Timeline that it takes a Drengin probe roughly 25,000 years to take a direct flight from Drengi to Arcea. If we assume that the probes are capable of an average speed twice that of the stargate for their travels, then this indicates that Drengi and Arcea are roughly two-thirds as far apart as Drengi and Toria are, which fits reasonably well with the distance estimated by the volumetric exploration rate model. While this by no means entirely validates the volumetric exploration rate model, it does indicate a reasonable degree of consistency between the model and the available data. I would therefore be willing to hazard a guess that the average speed of the Drengin probes is roughly 170 km/s (~twice the average speed of the stargate) and that the separation between Arcea and Drengi is 14 to 15 light-years while the separation between Earth and Arcea is about 24 light-years.
The end result of this is that my personal estimation of the Earth-Arcea stargate travel route would indicate that a 6-month journey would be required to travel 1 light-year. If my estimate of the average speed of the unmanned probes is indicative of the speed of manned spacecraft operating at sublight speeds, then the 10 million mile journey would take about 1 day of travel time; if the stargate's average speed is indicative of the speed of manned spacecraft operating at sublight speeds, then the 10 million mile journey would take about 2 days to complete, while if the speed of manned spacecraft operating at sublight speeds is similar to the average speed of the Apollo spacecraft on the way to the Moon (~3 days, 240,000 miles), then the expected time required to complete a 10 million mile journey is about 4 months. So, overall, I do believe that the 10 million mile journey is the one of shorter duration; however, this does not remove the possibility that it is longer. It's always possible that there are economic reasons why the sublight drives used in the Galactic Civilizations universe would be slower than the drives used to send the Apollo missions to the moon, and it's entirely possible that the average speed that I estimated for the Earth-Arcea stargate route is inaccurate, possibly significantly so.
