Linked groups are perfectly fine, and can share starship funds. (to buy a single starship) However, for a starship modification to exceed a starship's available emplacement points, the starship must be purchased new.
Players may also play lower level characters, if they wish, although it may be good to attach such characters to primary characters for protection.
As for starship crews, if your starship has a crew of higher than 1, they are by default of the quality indicated by the ship class you use. A noble or officer may expend a talent to increase crew quality by 1 step, up to the maximum of Ace. You're free to give names personalities to the supporting cast of the ship, but most often they'll just fade into the background and make your ship work.
As for the Yuhuzan Vong war, it happened, but it's remembered about like World War I. It devastated the galaxy, and nobody really had time to rebuild with the swarm war and the resurgance of the sith,which led to an even nastier galactic civil war, to the point where modern ship classes are an extremely rare sight in the galaxy. No one faction really has the resources to produce truly new state of the art ships thanks to the mass destruction of shipyards. Thus, modified versions of older designs, quite often built from scavenged materials, have become the order of the day.
Space dreadnoughts and superweapons occasionally get built, but the emphasis is on adapting old technology. Even separatist battleships have been dredged up from their crash sites, to serve in the navy of the Mandalorians. (OOC, these conditions are tweaks to cannon, and the main reason for this industrial devastation is so that iconic ships from previous eras can be used rather than having to make up random "advanced" ships.)
Game Mechanics: Many capital starships in this era have the junker template (with a corresponding 25% discount in price) and most supposedly "state of the art" vessels actually use many jury rigged or otherwise inferior components, representing base ship stats. A starship that truly takes advantage of modern technological innovations receives the advanced template, but the neccesary tweaking increases its price by 50%. (Most innovations discovered after the galactic civil war weren't really all that cost effective, due to disruption of industrial R&D due to constant war)
Primary Sith Empire Vessels: Tyrant Class Assault Ship (Acclimator Refit), Givnex Class Starfighter, Hapan Nova Cruiser, Imperial III Class Star Destroyer, Interdictor Cruiser, Lambada Class Bomber, Predator Class Starfighter, Executor Class Star Dreadnaught
The Sith empire follows much the model set forth by the First Galactic Empire, relying on hammer and anvil assaults held down by interdictor cruisers. They are also the only modern faction to have regular access to Star Dreadnaughts, giving them iron control over the Core Worlds.
Primary Fel Empire Vessels: Carrack Cruiser, Chiss Clawcraft, Imperial Assault Shuttle, Katana Class Dreadnaught, Pellaeon Class Star Destroyer, Victoria Class Star Frigate (Victory Star Destroyer Refit), Scimitar Assault Bomber, TIE Defender
The Fel Empire relies heavily on the combination of light but well crewed and commanded capital starships, combined with its elite corps of TIE Defenders. Most Fel Empire crews are of Expert quality, and the empire has recently taken to using a variation of hit and fade tactics against the traitors of the One Sith.
Primary Galactic Alliance Vessels: E-Wing Starfighter, Independence Class Star Destroyer (Mon Calamari Star Cruiser), K-Wing Starfighter, Naboo N-29 Starfighter, Nebula Class Star Destroyer, Nebulon-D Frigate, T-65XJ12 Jedi Starfighter, XJ Twintail Starfighter, YT-3400 Heavy Bomber
The Galactic Alliance still relies on large carriers equipped with unbelievably deadly starfighters. Even more than ever before. The Alliance still controls vast swaths of the expansion region and the mid rim, but they have a limited number of Star Destroyers to control so much territory with.
Primary Hutt Vessels: Baudo Class Star Yacht, Corellian Covrette, Corellian Gunship, Droid Tri-Fighter, Gallofree GR-96 Frigate (Medium transport refit), Gozanti Cruiser, Lucrehulk Class Star Destroyer, Skipray Blastboat, Star Galleon Frigate, YT-4200 Starfighter
The Hutts have only four vessels classified as Star Destroyers, all refitted Lucrehulk battleships armed with massive numbers of droidekas and tri fighters. However, they also have a frightening number of light capital ships, even if they've never even considered purchasing anything that might almost qualify as an interceptor. A massive hutt flotilla waits in the Ryloth system, where several border colonies have succeeded to the hutts, an alliance armada has been stationed to guard the planet from hutt agression, as tensions mount further.
Primary Mandalorian Vessels: Action IX Carrier, B-Wing Starfighter, Consular Covrette (Republic Cruiser refit), Firespray Assault Fighter, Jango Class Star Frigate (Commerce Guild Destroyer refit)
The Mandalorians have the most limited arsenal of the major galactic factions, however, their ground forces are also among the deadliest in the galaxy. A typical Mandalorian tactic is to deploy a massive offensive screen of Firespray attack ships to cripple enemy capital ships, then swat down enemy fighters with a line of Covrettes optimized for anti fighter operations.