Mission variable, subgoals etc

[Donneck]

Ok, so my problem is the following:

I'm creating a huge SP map. Player is supposed to be inserted by Blackhawk. When insertion is completed, the players waypoint is supposed to be shown.

Mission is to kill target person. When player arrives to final waypoint (airport = area 1), target person is supposed to escape to a nearby town (area 2) and finally be terminated there.

My problem(s):
I have to manage if target person somehow is killed at the airport => win Blue. Thats Ok. and easy.

But if target person leaves airport (and heading to the town) I must get shown to player his second waypoint sequence heading to the town, where finally I can kill him.

So there is a mission variable, if player does not manage to kill target person in area 1 (airport) must be redirected to area 2 (town).

How do I manage this mission variable ?

First I must have players waypoint sequence 1 shown from insertion by Blackhawk - to the airport.

Then (only if target person escapes) redirecting player to a second waypoint sequence heading to the town.

How do I make this mission variable ???

Other (minor) problems:

How (and where) do I design subgoals ?

Choppers refuse to land. Even if AI is set to follow waypoint Z, chopper does not land, its hovering about 30 meters above terrain. Why ?