We are all different and so our experiences - but your observations are good.
The joystick takes getting used to, that said dont think its too close.
Love my mirrors, little to no vibration even when going illegal.
I never like the look of the pannier and some owners was not over the moon so i never even considered getting. Same with Bluetooth - I use Cardo...
I get 155mile and don't really mind, I like taking a break every 2 hours- 36mpg
Tank width and shape is great, at least for me,. That said thick tank pad will change that.
Not had battery issues... your does not sound good. how old is the bike/battery?
Don't think weight is a problem with a low seat height, but that what you get buying the largest beast - handling is excellent.
The seat is very comfy, but not breathable so sweat easily
The Avons are awesome, getting to the edges and dragging pegs is easy.
Traction control and cornering ABS is very good and saved my butt a few times.