This is where you really start to get into it.
As for removing the un-used wires : It does keep things neat to de-pin all the un-used wires but if you end up needing them it
could be a PITA. I cut the un-used wires to about 2.5 inches, bundle them into groups by connector and encase them in heat shrink tube. If I end up needing a wire, I can pull it out of the heat shrink and solder the cut section back on. Again, it's your choice.
Here is where it can get confusing. You have decided to go D2D. That means that many signals are handled by the D2D connection.
Lets take the Tach signal. The FLCAN obtains that signal via its' connection to the trucks J1850 wire. It passes that Tach
signal to the Viper via the D2D harness automatically. Supposedly the Viper will use this "Data" Tach signal properly. However,
it is supposed to ignore the Data Tach signal is a Tach signal is hardwired to the Vipers' Violet/White Tach In wire. Interestingly
enough, this Tach In signal could come from the FLCAN's Purple/White Tach output wire or the truck itself at one of several locations.
As previously mentioned, the GM1 firmware has been known to mysteriously drop the Tach Output signal, both Data and hardwire. That
is the reason that I suggested going directly from the Viper to the White Tach wire at the instrument panel. Again, it's your choice.
On this same note about the Tach signal, it is possible to go into the Advanced setting while Flashing the FLCAN module and turn off
the Tach Output.
Yes, the FLCAN Pink IGN (+) In wire gets connected to the Vipers Pink (+) Ign1 output wire which continues to the trucks Pink IGN1
wire.
One thing to remember is that the FLCAN will only supply the front door status to the Viper. If you have a 4 door trunk, you
must add those door trigers to the Vipers' Door Status Input to ensure proper alarm monitoring. This is where you learn about
diodes. Here is the info on the rear door triggers :
Driver's Rear Door Pin LT BLUE/BLACK (-) BCM VIOLET CONN, PIN A3 (ALL MODELS)
Pass Rear Door Pin LT GREEN/BLACK (-) BCM VIOLET CONN, PIN A2 (ALL MODELS)
Diode info can be found on this site. You will need some 1N4001 diodes.
Are we having fun yet?

Now you can see why a good 12V shop charges the amount they do for a quality install.
Soldering is fun!