I think at this point it would be worth reiterating that games like Freelancer have a lot more of the framework you are looking for in the engine, especially in terms of procedurally generated missions, basically its more of a case of the modder sets up the region of space and sets up the framework for each mission type and what can be changed.
From what I can make out you are wanting SCP to add features specific to this idea to the engine and i can tell you that unless there is demand from more than one person or you being close to one of the coders the chances of this happening is bordering on nil. To stand a chance you would need to get together a serious proposal for a mod that you fully intend to manage and release yourself because there are precious few coders in the SCP and all of them are currently working on things the engine needs as a whole and projects that greatly interest them. Remember the coders are all volunteers who in most cases can spare at best a few hours a week between RL demands on their time such as work and families.
If you want to improve your skills in modding FSO there are two routes to take, first is to throw together a few missions for your own private enjoyment, if you think they are good throw them up here and see what happens. Secondly start working on a serious mod, not the idea you have now, either by starting your own project or joining a work in progress, the smaller ones can usually benefit from 1 more fredder to share the load.
During this you will make contacts that will be helpful when you come to make the idea you have right now a reality. Also while you are working on the above steps record all the thoughts, concepts and ideas relating to to the unending campaign down including Sexp requests that you will need. This way when you come to start the unending campaign you will have a solid base when you start and a clear idea of what you need, this will help greatly when requesting the needed features.