In answer to this post, my brother-in-law points out three issues with Bridges. I don't think any of them make the setting unsuitable for a RPG.
First is that they ruin the First Law of Thermodynamics because energy can be created freely. My brother-in-law provides a somewhat complicated example. A simpler example I'll share here would be using a Bridge pair to make a continual waterfall and then powering a water wheel with this continual waterfall.
No big deal for RPG purposes. The Second Law of Thermodynamics is important, but many RPG settings ignore it. I can do the same.
Second, a wormhole allows time travel according to general relativity. The Wikipedia article refers to a way to escape the problems presented by this issue: potentially creating a "feedback loop of virtual particles". In other words, accelerating a Bridge to relativistic velocities simply means if you bring it back near its mate they both will break.
Third, any source of free energy makes it much easier to destroy planets. An asteroid or spaceship could be inexpensively accelerated to a high enough velocity to shatter a planet it impacts.
This should change the setting so life support systems are illegal. Anyone who has a spaceship with a life support system could fly it away from their planet, eventually turn around, and fly it back fast.
Also, it reinforces why BridgeCo needs to have hidden monitoring and "back doors" built into the Bridge network. Since Bridges can be used instead of life support systems, BridgeCo needs to know the location of all ships with Bridges on them. Similarly, if someone was to travel to an asteroid by Bridge, start accelerating the asteroid, and periodically return to adjust its course, BridgeCo needs to know.
It would also make sense that detection of asteroids has improved since real-life current capabilities, and that BridgeCo has a collection of previously-accelerated asteroids at the ready. If someone else does manage to try to "crack" an inhabited planet with an accelerated mass, there may be time for BridgeCo to pick one of its asteroids moving in an appropriate direction, transport it to the scene, and "crack" the aggressor first from a direction that sends the debris away from the threatened planet.
