1. The N54 is a bit wobbly on idle, all the ones I've been in do it, I quite like it, it's nice to feel there's an engine there.
2. Is yours a manual? If so what you are describing sounds like the engine braking which is enabled in lower gears / lower speeds. To save fuel the engine braking is disabled at higher speeds to allow more coasting. (throttle plate is left open to reduce braking effect)
3. Wipers, AFAIK all E9x do this, all the ones I've been in past and present new or old (up to 2010) do this, it seems its just the motor starting jolt felt throught the bulkhead that supports the brake and clutch pedals. May be fixed on newer models though from other posts.
330i gone. 335i gone. E63 gone. M6GC current...