mhhh i thing you'r complicating too much the things...
mi way (newbie's hard way) is to set an waypoint far away, wher the chopper must whait until the squad seise teh town, and in the waypoint's "on activation" put this :
heli setvelocity [0,0,0]
this will full stop the chooper, then put a wayopint near the town and put a condition (in the waypoit parameter) : something like "whatever".
and then use a tigger when the chopper must go to pick the squad.. and add tthis line on the "on acrivation" field : whatever = true.
then put an waypoint for the group near the escrtaction zone, and add whatever to the "condition" field... and put an "get in" near it.
Then put a chopper's waypoint whit "load" close the "get in" of the squad, then sinchronize them...
i think this should work.... maybe mi english isnt clear enoguh to understand wolle the spaggeti.... but i think its clear
cheers ;D