Several ways to explain what you felt. The DC-9 has a heading select knob that works on the CAs side only and if you have it enabled and don't move it really slowly initially it will roll the airplane in a rather abrupt manner. Also, we are tracking VORs manually and have to adjust course a lot with the unreliable VORs out there (and constant calls from center . As far as the descent goes there is a trick there too that not all guys use. If you simply move the VSI wheel to climb/descend you will feel it in the seat of your pants. The trick is to first enable pitch hold and then move the VSI wheel - much smoother. Again, not everyone care to do this and it's technique only.