gear stick vibrates when idle

Is it normal that You see the gear stick vibrate when the car is running in neutral (idling)? V40 1.8 Petrol...

Pretty much, yes. How bad though depends on make model engine etc, oh...and if your gearbox mounts are ok. Hope this helps. Morphinemitt. Nipper said!

Engine vibrations felt in the steering wheel and the pedals, is this most likely caused by engine mounts, gearbox mounts or something else?

Again, it really depends on how bad the vibrations are. A lot of cars have slight feedback through the pedals, gearstick and steering wheel purely because of the way sound and movement travel, this and the fact that they all connect in some way to the engine which itself vibrates. Are you getting much feedback when the car is moving, and does it increase/decrease when you rev the car? These are all factors which could lead to it being either a trait of the car or a more serious problem. Hope this helps. Morphinemitt