Dale Sams, you are using the same justification the founders use to protect themselves from the 'evil' solids. To them there is no such thing as a 'civilian' solid. They see all solids as having the potential to hurt them just as you are saying all changelings have the potential to hurt solids.
Can't you see that what you are saying makes you just as bad as them? Genocide is evil and wrong when the founders do it, but its the right thing to do if humans do. Because we're the 'good guys' so anything we do is 'right'. After all we are just protecting ourselves, not like those evil founders.