Does it matter if you get to vote for your leaders, as long as they're benevolent?

Yes -- to be able to collaborate with others, to share it freely, to make sure anyone can always open and edit it, even if the software's original developer no longer maintains the project (e.g. Nina Paley, author of Sita Sings the Blues, is forced to use an old Mac OS X version just to be able to use Macromedia Flash).

Not to the quality of your work. But to your freedom and the possibilites of how you can re-use your work in other contexts.

What if you cannot edit your documents in ten years from now? There are more chances you will still be able to edit them in the future if you use free software.

Yes.

Yes, if you interpret "result" in a broad sense, as to encompass society as a whole. And you should -- no one is an island.

Yes.