I'd shrink the size of the UE, and Pull the Andorians and the Vulcans in. We have a canon statement in Season 4 of Enterprise that Vulcan is 16 Ly from earth (Which fits with it being the real star Omicron² (40) Eridani A), and the Accepted Fanon conjecture is that Andor Star (The Gas Giant that Andoria [a rather large moon, and the home world of the Andorians] orbits is Andor) is Procyon A. Procyon (aka Canis Minor) is only 11.41 ly from Earth. Here are a few Maps that are of real stars to help you out.
I'd drop the Zacdorn, and Use the Denobulans instead
I'd like to see a few more Andorian, Vulcan, Tellarite, Human, Orion, Denobulan, Tholian and Romulan Ships. The Tholians are butting up against the Humans in the Mirror Universe in the ENT era so I wouldn't be suprised if they were about to do the same in the Regular Universe.
EAS would be a good place to start looking.
Specificly I wouldn't mind seeing:
Surak and Sh'ran (Vulcan); Kumari (Andorian); Intrepid, J, Y, and Neptune (Human), Orion Cruiser (Orion); Warship (Tellarite); Drone and Bird of Prey (Romulan); medical Shuttle (Denobulan), and Tholian Cruiser (Tholian).
ST Dimension has a few very good maps, analysis, and conjecture about the structure of the Federation "Core" Worlds.
I know that's a lot, but most of it is just canon stuff from season four of Enterprise. I'll try to play your scenario when I get the chance. I'l willing also to overlook most canon violations if it has good game play.
