replacing case...what to do

so i got my macbook in august of 2008
i love love love it, i have the macbook protection program till august of 2011
heres are the minor problems....
my lower case is basically falling apart....about two inches away from the track pad on the edge of the computer there is an inch (length) of a missing piece, i didnt drop it, but today i was typing and all of sudden it began to break off, same goes for the left side corner parallel to the monitor chipped off, the bottom of my computer is complete other story....i think the heater melted something cuz the bottom of my macbook is disfigured and so gross...none of these have affected the computer itself but im worried it will in the future.
can i go into the apple store and get it replaced...(for free? possibly) oh another minor thing my monitor has this line going across in the middle, it isnt that recognizable but sometimes when i watch movies its very vivid.
anyway i dont want my computer replaced i have alot of info in this badboy that i need, i just would like the case replaced...what should i do
THANK YOU SO MUCH

i love my apple lol