Older Subaru models could be put into 2WD by removing (or adding; I forget) a jumper fuse in the fuse box.
I doubt that is still true in 2013. In any case, I would not suggest you disable AWD in a Subaru by removing a mechanical shaft.
I honestly do not think your fuel economy and acceleration will be much improved. Most of the torque is directed to the ...
On most vehicles, the entire dome light assembly can be removed, or the cover popped off so that the bulb can be changed. You should be able to carefully pop it out and gain access to the light bulb and wires.
Most dome lights have three wires:
power when the door is open
There is usually a 3 position switch. When the switch is in ...
chrisfix has done a very good video on how to install an auxilary light. youtube link
the only difference is in your case the lights are going to be inside.
basically you need to do these
Find out the wattage of the lamps
Create fusible wire link with proper ohmage calcuated from lamps wattage
Find a way to move your wire from under the hood to inside and ...
Take the existing light out and test, using a test lamp or multimeter, each of the wires to find the one that is live.
This does assume that the existing lamp is working otherwise you need to check the supply.