I think you should totaly go ahead since Greenlight is made for that, i mean if anything important would be missing to the game you could anyway update the game with Steam, and you could have a great opportunity to get alots of reviews so you can easily and quickly know what is missing and what could make the game more great
![Smile :)](./images/smilies/icon_e_smile.gif)
You shouldn't be scared about that, Greenlight is made for that
![Wink ;)](./images/smilies/icon_e_wink.gif)