3- tach wire, I connected it directly to the coil pack in the engine bay, I dont think I hooked up the neutral safety switch.
the second 3 - I dont think so
4- mine unlock all doors on first unlock
no relays used ( havn't hooked up trunk release or dome light yet)
Mine is an 04 XLT and a Clifford Matrix 50.5X (basicly the same thing)