1a) You can't, unless you get scripting. However there is an addon somewhere, no idea where.
1b) No, you're not.
Check the Ed Depot - Tutorials - References for a complete listing of weapon and ammo names.
2) Choppers are a whole field of interest within OFP. There are a couple of tutes in the Ed Depot and plenty of stuff on the forum - use the forum search function to find it.
You little extraction script doesn't appear to do anything except move the chopper to the postion of whatever vehicle SAS1 is in, and you can do that much more simply - as you have - with chopper1 doMove getpos SAS1. What you don't have anywhere is an instruction for the chopper to land or an instruction for the SAS loons to get into it.
Getting choppers to land and pick you up at a given place (where you can pre-place an invisible H) is hard enough, doing it whereever the loons happen to be is even harder. Master the first before attempting the second.
If you haven't already, learn about GET IN and LOAD waypoints, and the command
land. Commands assignAsCargo, moveInCargo are worth knowing too, even if you don't actually end up using them here.
Oh, and
Welcome to the forum!