Hi there.
1. I have used it in all three positions and found mounting it under the fingerboard gave the best sound with my bass. Second was under the bridge and last was under the tail. All three positions gave a very accurate representation of the sound from my bass. It also blended very well with other pickups. I found that with a bit of experimentation and patience the best sound position could be found.
2. It us very snug so should be fine for a bit of bass acrobatics. I played in a country band standing up and moved around without any problems.
3. Yes it picks up all sound from the bass.
4. I used it in the country band at rehearsal and live with a moderate drummer with no problems.
Hope this helps.
Marc