The symbol is for "Speed limit assist" and is based of a forward facing camera that allows detection of the speed limit and then possibly displays this on the multifunctional display.
Information can be found at this site, under the "Steering Wheel( 12 button multifunction...)" > "Assistance menu" and subsequent links from within page.
It sounds like the dimmer switch is set to off.
The car's dash lights are on a dimmer switch. That switch allows you to change the brightness of the lights at night. The switch is capable of switching the lights from full-off to full-on. Also, it is not uncommon for dashboards to have their lights on during the day, while the regular lights are off. This ...
It looks as though you could add a third party CarPlay-compatible receiver to your vehicle. A quick search on the Crutchfield site shows me at least 50 options.
Even if you do not choose to purchase from them, their site is a great source for market research.
Full disclosure: this is what I did on my 2004 WRX and I used a receiver from Crutchfield.