Welcome from Canada. Unfortunately the parts situation is not great. It pays to order a few items to keep ahead, such as spare cables, hoses and gaskets. Enjoy your ride.
When I refill with gas, my 2014 RT takes a mile or two of riding to register on the fuel gauge. It seems to be a common trait of these animals. So in other words, it probably is fine and will start to work when ridden.
Sounds like you have done the normal cures. There is actually an idle screw under the Bearclaw. i think it is coloured (maybe yellow). Normally adjustment is made through the ECU settings. Good luck.
I think that some Provinces require "Winter tires" to be fitted between certain dates. Anyway that is what I was told. Where I live (PEI). we don't have that law.
I remember back some years ago when another member (Alberta duke) was having similar symptoms . Seems to me it was a glitch in the Tune he was using. A more suitable tune took away the problem.