By Nepleslian, I mean those dwelling in Nepleslia in general. In other words, Geshrin, naturalized Yamataians and elves, etc.
Also, Freespacers are not part of the Nepleslian government, and probably never will be, considering the fact that they hate us immensely.
As far as introducing amendments, the process starts waaaay down at the bottom, in the Planetary state's legislative bodies. If enough people like it, it may boil up to the Senate itself. If you have an idea, you can run it by us, but we actually will be voting on that kind of thing, so passage isn't guaranteed.