Engine problems
 

I have a 04 RX8 with 91,000 miles it idles rough and sometimes looses power and twice has died and it takes a minute to start. Today it started loosing power real bad and it felt like the clutch was vibrating and making a weird metal to metal noise, could all this be due to loss of compression because I would still be covered under warranty. Please help the dealership is coming to pick it up today and I don't wont to be hosed.

when was the last time you had the engine serviced? plugs/ coils changed? Check your cat to see if it's clogged or damaged

If it's still under the warranty, then just have the dealership to fix it for you.