Ok, gotta weigh in...Smoke ring in Chicken... Nope! Not enough Myoglobin in the muscle to react with the Nitrogen. Takes Red Meat to get a good ring, although the Legs may get a little pink.
Smoker at 265*F...Crank that BadBoy up! 300*-325*F, The Biggest advantage of gassers is they get Hotter than Electrics and will give you a nice Crispy Skin.
Mushy Meat...Your brine was really light on salt. You gain little with the Boullion Cubes and they cost $. Use 1/2 to 1C Kosher salt per Gallon and add 2T Dry Parsley to what you already use and you will get the identical flavor.
Lose the Water Pan... in this case it is not needed and gassers generate plenty of moisture just burning Propane. You Steamed the bird mushy. Also Tent with Foil don't Wrap, again generated steam.
What to do with the JUS...Add it any where you want some smokey flavor. Rice, Beans, Soup, Gravy, Pasta Sauces, Vegetables, Mashed Potatoes YUM!, any where you might add a little Chicken broth to.
You did a great Job and learned a lot. BTW...Love the Glasses, very 70's and you are a total Cutey!...
...JJ