Yes. Note that this is still considered to be short range.

Yes and No. If a unit in not engaged in hand-to-hand combat, then a flying high creature can only attack it from the front. If a unit is engaged in hand-to-hand combat, a flying high creature can attack from the flank or the rear.

The flying high creature may attack the unit in the flank.

Yes. Play it that fliers are not effected by the 'defended obstacle' rule (i.e. they hit normally). This isn't stated specifically in the rules, but is implied by the description of how flying creatures fight and the driven-off rule (i.e they are flapping around, not standing on the ground).

This is not covered in the rules. The following house rule is good: The creature can flee and is considered driven off, like voluntary departure from combat.

No.

The flying creature gets to pursue the unit normally.

No.

When a flying creature is driven off, it must miss an entire turn (Movement, Shooting, Hand-to-Hand Combat, Magic) for its controlling player, then it must return on controlling players deployment board edge.

In other words, if at the end of the controlling players turn a Manticore is driven off, it stays off during the opponents turn (Movement, Shooting, Hand-to-Hand Combat, Magic) as well as the controlling player's turn.