As presented in the movies, there are ways to teleport ships around battlefield through special engines or modules (as I suspect).
Here are some ideas how this teleportation could be used in... more creative way:
- Teleport an unexpected ship armada right into "losing" scenery of battle. Serious debt included.
- Teleport basically anything into battle scene: how about creating a vastly huge cannon right inside the empire/territory, then using this cannon to generate enormous blast of energy targeting nearest active portal. Then open this portal right nearby enemies' main ship, leagues away, blasting it into tiny bits as completely unexpected action.
- Move Your forces around galaxy as needed and requested.
- Catch a moving asteroid into active gate, and then release it right nearby enemy fleet, crushing them utterly.
- When a player would like to join ongoing battle, his /her ships would use this kind of technology to arrive.
- Open portal right before fast moving enemy ship, so it could not maneuver out of the portal. Teleportation sends the ship directly into nearby star/sun core.
- One crew member activates a grenade inside his ship. Then teleports this grenade right into enemies command center, annihilating high ranking members. Enemy fleet scatters and flees.
- Board other ship by teleporting commandos.
- Launch a missile. Target small teleport. Open it behind enemy ship shield. Profit. Bonus points when opened inside enemy ship fuel storage.
- Open small gate. The other end opens inside enemy command center. Your hand goes into gate, and clicks "self destruct" on the other side.
- Portal Shield: When ship manages to properly analyze trajectory of a bullet, laser or missile, its systems open a portal right in front of it. The other end of portal opens nearby, but in opposite direction. Result is that each attack upon this ship would be targeted to the attacker.
- Ultimate Self-Destruct Collision Warship: A ship, that teleports itself right INSIDE target enemy ship.
- Utterly Plausible Galactic Uber Troll: Get Your fighters camo-ed into Your enemy fighters. All colours and banners included. Teleport them right inside enemy carrier. Make enemy fuel them up, gear them up, and release them upon "their foes". Bonus Points for destroying the carrier using it's own bullets.
- Utterly Plausible Galactic Uber Prank: manage to teleport infinite balls into all manageable places inside target warship. Decrypt all WTF messages. Raise morale of whole fleet.
- Teleport a ship vertically. Bug out the game.