While reading some forums I got this idea from a few different posts and wasn't sure which one to post it in so I decided to create my own.
On the topic of dead planets:
There is a ton of them around and it is aesthetically pleasing cause it adds a certain amount of reality to it considering the Goldilocks zone etc. This seems to me to be about the extent of their usefulness. With this in mind I think that Dead planets could become something akin to space stations. Not really colonizing a dead planet but put a way station of sorts on the planet. Their could be multiple uses for these types of stations -
1) A Refueling Station - Whether that be like a moon base or an orbital platform. Taking from another forum thread about the distance in which life support system would function. This would increase a ships range but nothing to drastic as to take away what a space station would give you. Also I would see this as nothing to expensive or extensive to make huge impacts on game play or functionality.
2) A Staging Area - I like this as an added strategic element to the game. When your starting to assault on an enemies area you could begin by taking out their planet bases/platforms to create staging areas for your attacks while you work towards their main planets. This of course would not be necessary to do in order to conquer their area but could ease the progress. I would also limit any bonus you would get from it to keep from unbalancing the game and keeping it as a fun feature and not a requirement.
3) Tech - In the tech area of the game these types of bases/platforms could be used as *minor* enhancements towards certain types of networks -
A) There was one forum post about the creation of space roads, traffic areas, and well other travel based ideas, these stations/platforms could be used as connecting points or something along those lines.
B ) It could be used in the creation of weapons such as planet destroyers (if they ever come) or add little tweaks or requirements for certain weapon systems based on the material or the type of dead planet..ex- need a certain type of mineral or gas that you can only get from said gas giant etc.
C) The creation of certain types of fields or sensor readings could be created by these bases/platforms. Use it as a scouting base etc. or create some kind of distortion in space near the planet that makes enemy ships passing move slower or have reduce sensor range etc.
4) Random boosts or Tiny Events could be derived from them - "an explosion at the station has set research back one turn" (nothing to extensive maybe even one turn is to much based on the number of dead planets and the number of the events would have to be regulated so they didn't happen every turn or all at once. This could be an added feature to the one already in the game for when you first colonize a planet.) '
5) Espionage - These types of bases/platforms could be used as easily infiltrated places to get sensor data or view an enemies' area and movements. So Less risky places to have a spy (I would suggest the view created by the spy be limited, not like being able to see a whole system but just enough to see passing traffic etc.)
6) Pirates - So the Devs said that pirates would be included in the game and i'm not sure if they are going to want them to be able to conquer your worlds or just harass but these types of stations would make prime targets for them and create more interactions between you and the pirates. (This would have to be regulated as to not force you to have to go and take back your stations every turn. Eventually allowing you added tech that protects against the pirates)
Now all these ideas would have to be limited in bonuses, cost, or effect of these types of additions. I would think they would work better as minor additions and extra stuff you could do then to make them a large aspect of the game and creating a million balancing issues. There is also a lot of these planets so their bonuses would have to be limited just so that no one could exploit them thus making the game to easy and losing its value. I would also like to note that the bases/stations health i.e. what it would take to destroy them or capture them be very minimal to reduce any kind of tedious task that could take hours and take away from the main aspects of the game. Also my intent is if these where to ever be created is that they be as maintenance free as possible. You already have so much you can do and will have to do so by adding a ton of maintenance with stuff like this would detract from the game. My intent with these additions is to create options and different avenues that one can take to creating their galactic civilization. Also I apologize if these ideas have already been spoken, discussed, or utterly decimated by those that wish to see us all destroyed.