07 mustang gt alarm

Thanks for reading, I will be installing an alarm in my 07 Mustang, I used to install like 5+ years ago, I was wondering if anything has changed since then, also from the wire diag I have found on this site it says the door have a neg. trigger? so can I just reun the - wires from the alarm to have them work the door locks?  when I used to install most of the Jap cars were like that all american cars were either 3-wire + or 5 wire +

Next the door trigger? can i just hook up to the dome light? or is there 1 for each door? what polarity is the door trigger? used to be + but I noticed on the wire diag. it says they are now -??

Last I dont have a factory alarm, onle the transponder key I think ford calls it.  Does this mean I will not have to hook up the starter kill relay/circuit?

Thanks for reading!!

Yes technology has evolved a lot since 5 years.  Starters, alarms, bypass modules the works.  What you need to know is now you are not messing with a car you are messing with computers on a network.  No big deal but keep in mind that it s not like back in the days when everything use to work on high current.  Now almost everything work negative driving relays or multiplex using resistors.  Now take as an example this Mustang (door pins)  test negative when the doors are closed and test nothing (open) when the door is opened!!!  Kinda funny!!!!

Anyways let me know if you have any questions..

Eric