A nice, quality, 1/2 inch drive torque wrench is a great investment. The Sears/Craftsman version is fine. Be sure to use new crush washers above all else.
Honestly, I don't torque the drain plugs. I use new washers each time and I tighten until snug and then a bit more. Yeah, it's not the correct way, so sue me.
Gas- You could have 8-10 gallons of gas in the tank based on the gauge reading half full.
A hose about 4-5 feet long should work just fine with your drill pump. Be sure to cover the fendor with towels or rags so as not to drip any fuel on the paint.
Good luck.