In all probability the main considerations of designing a commercial aircraft involve conservative factors of manoeverability, fuel economy, general structural strength with minimum weight, maximum cargo capability, ease of handling and other factors which make a good aircraft. To radically distort these aims towards safety in a disastrous situation would surely compromise all the factors which make an aircraft useful and profitable although I'm sure safety is a factor cosidered in a design. I sincerely doubt major structural changes such as you suggest would be considered in the light of the other elements of aircraft design.

The risk of dying in a plane crash is hilariously low. So much so that most accidents, even minor ones, make the news.