'02 zx2 problems...

Actually, there are a couple problems, maybe related? 1st was the VCT, car was running rough, stalled while coasting or changing gears, changed the oil, much better. Still stalls, but not very often. 2nd, newish whining sound. Strated when it started stalling. Faint whining, gets higher in pitch as rpm's go up. 3rd, cluch feels weird. doesn't happen all the time, but will sometimes feel like theres no resistance to it, usually happens when shifting while going on or off highway... today it started bucking while in 3rd for what seemed to be no reason. Any suggestions? Thanks for any help!!!!