If this game 'were' to be realistic, then anything you collide into will give you massive damage, and insta-boom for fighters. Why?
Like Ortiz said, all your 'shields' are only good against energy based collisions. If I toss a rock at yer ship, it'll hit the hull, since it isn't carrying any charge or energy with it.
The only shield I can imagine to stop physical things is the Graviton shield, since it said it creates a gravitational force field around the ship, to stop physical things.