I am not sure i should take the bait a and c but you are very wide of the mark.
I actually agree with your comments about basic skills, they are important to have and equally important to be able to fall back on.
However the cirrus has much more redundancy that you realise. There are twin ifr gps, the screens are now independent, capable of each displaying the vital information and driven by independent computers. Then there is the hand held gps in my flight bag that will power up in oh um about 20 seconds and needs only a gps signal. Finally there is atc on box 1 or box 2 or the hand held also in my bag - please sir i have lost everything how about a vector there is a good chap. Dedicated followers of the purple line with a well packed flight back are really very unlikely to ever need to revert to da should they prefer not to.