Do yourself a favor and buy a tube of Sil-glyde form napa and use it to lube the caliper bolts/pad clips. Stuff is seriously the best and a tube will last you a long time.
being a turd owner, and my girlfriend owns an 04 ion, you only need to change the hardware. you can bleed the brakes but if you want, but if you dont need to then you dont have to.
and +1 to that^^^^^, lubing the bolts makes things easier in the long run.
Brake fluid absorbs water (not silicone brake fluid) and all the crap ends up at the end of the line/system which would be the caliper. When ever i replace front pads i clamp off the rubber hose and open the bleeder to push the piston in. Doing this will force most of the crap out through the bleeder. You really dont want to push all the crap back up the line (without clamping) and into abs units ect… etc… When i finish i usually bleed/take 1 pump out of each wheel i serviced. Many times i will just gravity bleed the caliper i just compressed with also works well.