It can fuck up your transmission and clutch. You asked in the thread title, "Symptoms of a bad pressure plate" the clutch will slip. Sit on a slight incline I dunno 10-15 degree hill, put it in first gear let out on the clutch just enough to hold the car in one place for an extended period of time, if the car rolls backwards your clutch is either gone or your pressure plate is fucked or you need to adjust the clutch.
93 Si - 13.7@101 all motor/street tires stock head bishes...
2006 Laguna Blue Pearl S2000.