OK... Good question, and one that will be looked at and fiddled with heavily.... Here is the consideration of the universes...
B5: Heavy Hulls and good weapons... Fighters maneuver well, but big ships are mostly sluggish.... The few that do move well at all have medium to light armour... This applies to the younger races that I have seen in the series... As for the vorlons, and shadows... Almost all there ships (except for their huge ships) move very well.... Shadows very very well.... Adaptive hulls, and excellent weapons.... More on that later, and it is up for more debate later I am sure!
Star Trek: Heavy shileds, good engine systems, very adaptive, and good weapon systems, but medium to light hulls.... CLOAK being a biggy, for it is used more in this galaxy than the others...
Lastly they have the photon and quantom torps... Those will come into heavy play, and effects... Most of the ships they have are cruisers, or caps anyways, so they bring a big plus to their aresonal! Plus lets not forget the Borg...
Star Wars: Their big ships maneuver well, and are very well armoured... Weapon systems are pretty heavy as well... The use a mild shield system (deflectors) The smaller ships have extreme speeds and maneuvering... Then their is the "force", and the death star to consider as well.... Lets not forget the mind boggling numbers the empire has aquired... And considering how star wars is based... It may have more advancements than the other galaxies...
I am sure their is a dozen more things that can be pointed out, and exploited... That will be covered over time.... Big things are getting the models done... effects... textures... then we can balance out the tables as the missions are being built to tell the stories that will unfold! That is why I need help from everyone! To keep it true, or at least close to true to all these universes to create that unique experience that this calls for!