A possible kickstart goal might not just be to hire someone, but perhaps part of it could be to cover the cost of a promotional/publishing company (Think IGN, or something smaller) or social media pages to advertise this project so more people can come and check it out, which may lead to greater things such as more interest in people who can assist in the project beyond donations.
I have a hard time imagining kick starters getting behind a project to pay to promote an unfinished game. That's pretty indirect.
Some interesting bonuses for donating certain amounts could reward the donator with something in-game, as a way to credit them. Think of pre-order bonuses in a way with games you buy from retailers, if you give them small incentives, that helps entice people to help out. I'll just throw some out there, even if they may not be suitable:
-Donators formal/legal name listed in credits
-Star System name generator list includes their formal/legal first name / surname
-If you were to set up a log-in feature for the game, the donators account (if logged in) could recieve small bonuses that aid the player at the start of new single player games (Extra booster resources).
-A custom requested ship design which is unique for the donators game and no one elses (this would depend on cost of labour/amount donated to suffice the time to create the requests).
-Donators could receive newer version releases earlier than sourceforge releases.
This is an open source game. And we intend to make an keep the content as easily editable as possible. Most of the rewards you mention could make sense in a closed-source game, but wouldn't work, or loose a lot of their punch with us. Anybody can edit the text file that contains star-system names for games they host, for instance. Not exactly the same as everybody seeing your name, but close.