The black grease is normal. Vibration is not, especially for 3-D printing. Check that the surface it is mounted on is secure and stable. If you are comparing the SM to experiences with a belt-driven printer, the SM will be slower and will vibrate more due to the leadscrew design of the linear modules. Awhile back, I came across some posts which implied that the effective speed of the SM is about 55 mm/s: people use it faster than this without problems, but if you are having vibration issues I would recommend dropping the speed down to 55 or less and see if that improves things.
See the staff post for recommended maintenance:
How to maintain the snapmaker in perfect condition