Moving into and leaving enemy threat zones

As a relatively new DBA3.0 player I am looking for a few clarifications on threat zones. These are;

1. When an element (or group?) wants to or moves into an enemy threat zone does it have to in fact end up parallel to the enemy's front - lined up or not lined up but still parallel? The descriptions around Figure 7 on page 18 suggest this, and that one cannot leave a disrupting Psiloi at an angle in a threat zone in front of a line of spears say, and;

2. On the same figure under 7a point 6 I understand that the element can move out of the threat zone 'straight backwards, this makes sense. What if though an element approaches an enemy element from say the rear flank and stops within 1 base width. This puts the enemy in a threat zone. But in that enemy's turn how can that element move out of the threat zone 'straight backwards'? Straight backwards would be towards the element producing the Threat Zone? Clearly a good tactic.

I have been playing this that the affected element can move directly away from the front of the element producing the threat zone, ie on a line perpendicular to the attacking element. The element moving out of the Threat Zone can end up in any orientation and distance under the normal rule constraints - is this correct?

Thanks - Phippsy