That all sounds reasonable. For anchoring the hose to the shoulder strap, a piece of 1/8-inch bungee or even a fat rubber band will also do the job.
The "trick," if there is one, is to not pack the pack too tightly so you don't put excess pressure on the reservoir (which can force water out through the cap, into the pack). If it's warm, wrap it in clothing to keep the water cool. If you're paranoid about leakage, packing it inside a stout plastic bag can catch the drips.
I used to use a 2L Camelback inside the pack. I just let it sit against my back inside the pack. I actually cut an eye-shaped hole in the pack to put the hose through - but you should be able to let the hose come out of the zipper.
You can buy hose clips for pretty cheap that clip on your shoulder straps and hold the hose for you.