havhon

1) What is the stock speaker wire gauge from the HU to the speaker(s)

2) From what I can gather, it is next to near impossible to run new wire through the door boots. It appears the harness(es) running through the door do so via connectors, leaving us no way to run new wire w/o drilling new holes......my question is, is this a true statement

3) Is the stock speaker wire good enough to handle 50 watts @ 4 ohms

4) Also, do I need these adapters to install my new speakers http://www.sonicelectronix.com/item_...-5600.html???? I am assuming the stock wiring already has these.....assuming thats true, all I need to do is possibly splice in new spade connectors at the and for the new speakers, or solder.

GATORB8

18 AWG
Sounds like you have a Dearborn built truck with the molex connectors at the doors. Only option besides drilling the jamb is trying to drill out the open area in the molex connector.

Yes, you should be okay up to 100W or more.

You don't need them, but if you get them you won't have to cut and splice the factory wires.