hey mate can't help you on the top 2
but as for the stuff to make it start, i havnet worked specifically on ae71's but its prolly pretty simple
there will be a few wires that go to the gearbox to tell it to only start when its in "park". just a matter of finding these wires, and experimenting with them to see which combination will make your start (shorting 2 of the wires with a spare peice of wire, and testing if its starts), i don't imagine there are that many wires going to the gearbox.
ive done this method on 2 s13's, worked well.
once you find out which 2 wires need to be closed to make it start, you can put a switch for it somewhere in your cabin and use it as a kill switch.