Hotwire Wiring questions

Finally broke down and purchased a wiring harness and PCM. Reading over the instructions and found alot of wiring I've already completed in my American Autowire harness. I've got a few questions...

For the wires down below... Are they needed to run the car or can I run the fuel pump using the American autowire harness?

Open Wires (wires vary by harness options)

a. Red – 12 Volt Hot at all times. (direct to battery) - OK
b. Pink – 12 Volt Run and start. (ignition key on position) - OK
c. Yellow – Ignition start. (ignition key cranking position only) You must use the included starter solenoid wiring for the engine to start properly. (Mopar muscle cars: You will need to use a momentary push-button starter switch with this wire on one post and 12v on the other post, the dual ignition circuit of a late 60’s to early 70’s Mopars will not work with the Hemi system) - Is there a work around? I really don't want to use a push to start button and a key. I'd rather just use the key.
d. Blue – Brake light output to rear brake lights. - Needed? Why
e. Purple – Backup lamp output to rear backup lamps. - Needed? Why
f. Orange – Overdrive off Switch to momentary ground. (optional, automatic only) - N/A
g. Blue/White – A/C compressor clutch. (12 volts to activate compressor) - OK
h. Black – Clutch safety ground. (manual trans) This must be grounded in when the clutch is pushed in or in Park/Neutral on a non-electronic transmission. - OK
i. Green – Speedometer output to gauge. - OK, but can I use the output from the Viper T56?
j. Grey/Black – Oil Press Gauge (open on both ends for you to hook up your own sending unit) - OK
k. Tan/Black – Engine Temp Gauge (open on both ends for you to hook up your own sending unit) - OK

I guess what I'm asking is why does the engine harness have controls for some non-engine related items? OR does the PCM need the input from these items?

Thanks,

Riddler