You can see how important supporting characters are. Not at all. You're using four characters to take out a single character. With support like that, the Dark Lord will be difficult to take out. Jedi Knights has many powerful cards and combos but for each powerful combo there is a way to counter it.
Every combo has a counter combo.
Since you indicate a character or starship is supporting by rotating, you may no longer attack that turn with that character. Old Fossil is an exception because he can ready himself after a battle if he is supporting during a battle you win. Just remember that it is a calculated risk to add support. Even if your characters survive weapons fire, all supporting characters are discarded also if you lose the battle. You will need to decide how much support to provide your leaders and hope that you can out-power your opponent.