Personally, I hate synthetic leather because it doesn't transfer heat away the way real leather does. My number one preference would be real leather, number two would be cloth. The ultra white is pretty and cleans easy, but I'd prefer function over form.
No, this is a problem that has always existed in all vehicles with synthetic leather seats. My X has ultra white interior without vented seats, and I have driven signature series Model X with ultra white seats with perforation and ventilation. The ventilated seats in the 2016 signature series are actually worse even with the fan on because you simply end up with less surface area to absorb/transfer heat and don't get that much airflow. Vented and ventilated seats suck in every experience I have had with them. Cooled seats (peltier element with some air flow) are better than unventilated seats, but properly cooled seats (A/C source and major air flow) are awesome.
Umm, no... Even low-to-mid-tier furniture has leather seating surfaces, and I'm certain vehicles under 100K did as well when I was shopping around before purchasing my X. You may have to spend $125K to get a vehicle where the dash, bolsters, console, etc. are real leather, but the seating surfaces are still leather in anything decent.