Welcome to Discovery. Glad to see you want to join a decent faction, and I'll kick the Admiralty chat until someone lets you in. As for ships, get a Templar. A crusader wouldn't stand a chance against a chimera. Alternatively, go for a Hussar and be very difficult to hit or a Paladin and be slightly underpowered. If you've got any questions about anything, pm [The_angels] or any of my characters, and if I'm not in combat I'll try to help you out.
In response to your question, no, we can't, otherwise we'd have bombed New Tokyo to ashes long ago. Of course all of our planets would have been eaten by Legate raids and practically no factions would have any bases left, so I think it's best that we don't have that feature