Once the game is released I do have future ideas for more content BUT likely not incremental additions. So the game ideally will be feature complete at launch. A while down the road (year or more) I may release a new version with more content and more things to do. But I have no idea if I'll actually have the time to do that which is why I'd like to just release the game as "complete". And then see what the future brings.
One thing I could think of to make this F2P is customize the ship and bridge with custom sprites and colors you could pay for. But that would be a lot of work to implement and I'm just one person.