Welcome to the boards, strat!
Let's see if we can answer your first set of questions here...
Screenshots of ships? Look around the site a bit more and you will find plenty of screen shots. All of which are straight out of the game.
Release date and method of distribution are all up to the publisher but as soon as we know more, so will you! (though a birdie might tell you within 6 months)
When you set up a random galaxy you will be able to choose a basic size of the galaxy, economic and research efficiency and the number of words the player starts with in their empire.
And yes the game will be very moddable. As game makers we have always been big fans and believers in the modding community.
As for the rest of your questions, perhaps its easier for me to explain the design philosphy of SOTS first and then get down to some details. SOTS is an attempt to depart from the "spreadsheet" aspect of some 4X games and get back to concentrating on interstellar warfare using the power of modern computer and graphic cards. We wanted to put the player into the position of Stellar Emperor/Admiral and NOT a Bureaucrat/accountant and so we placed the strategic focus on aspects that gave you more tactical choices instead of just abstract number changes. The focus is on starships and fleet design, not on the planets themselves. And so each race has over 70 ship sections to mix and match and dozens of weapons to load into those sections but planets themselves are controlled with a handful of slider bars.
Diplomacy is a matter of alliances and non-aggresion pacts. The AI will seek political situations that are advantageous to itself but will not mindlessly seek peace treaties just because a race is rated as "peaceful". As far as internal politics goes, the player is the one making all the decisions. When played by the AI, each of the 4 races will have a distinct style of play but not so much so that they will be utterly predictable.
I hope this helped with some of your questions, look over the rest of the site and perhaps you will find a few more answers and some more questions.
Once again, welcome and enjoy your stay.
--MEC