I noticed when I turn on my car (11 wrx,44k miles) from a cold start it idles at 1500.. And as it heats up it drops to idle around 900. But lately when driving from a cold start going from 1st or 2nd to neutral / stop. If I'm around 3k rpm. It will drop to 2k with the clutch all the way in. And stay there for a second or two then drop down. Also sometimes not all, when I push the clutch in it takes a few seconds for it to disengage.. It never took more than a second and I've noticed this. Is it normal? Also maybe a month ago I went to Subaru and Because sometimes when going to idle reve would drop to around 5 or under and the car would shake like it was stalling. It's my first manual and am a little confused.