adding window controls
 

I am disabled from birth missing most of my right leg, part of my left arm and a few fingers. I have difficulty using the window controls where they are and was considering adding a set in the arm rest console in the middle of the seats. My question is if they would even work after I ran the wires to splice into the existing door controls?

As long as you match the positive and negative wires then you should have no problem with them working. And if you're really unsure about it then hook some wires to the new switch you are going to use and test it before you fully run the new wires.

The way I would do this is just splice in some extra wires to make the OEM harness that plugs into the OEM switch long enough to make it to the center console and mount it.

This is what I'd do too. Just extend the whole harness and use the OEM switch so that you know it will work properly.