Hi,
I'm not using BS2 but anyway: some ideas for your problems:
1. In some cases, zoom on z-axis is limited by the game (to avoid non-realistic zoom view for targets). To apply a zoom in lateral view direction you have to lean forward nevertheless to the cam. This is not natural but it only works like this. For the inversion problem on back view check up this optons:
2. This is probably a problem in the model dimensions and (or) model position section.
Both has to be well measured and filled up. Mainly the model position is a little bit tricky to adjust.
3. How did you set up your curves?
4. and 5. The best position is on axe in front of the clip on the top of the monitor.