The flying wing would be a new "type" and therefore require a new type rating (special training on all the systems and performance) which is not super uncommon for new aircraft. As such it's not a big deal and any quirks would be covered by such training.
The 737 fiasco was almost entirely because they refuse to allow new 737 designs to require a new type rating and therefore force weird aircraft/cockpit designs that would otherwise seem stupid.
Also, commercial aircraft aren't really certified based on how they handle stalls, spins and spirals. Swept wings already handle those situations very badly and therefore systems are designed to prevent the aircraft from entering those parts of its flight envelope.
The 737 fiasco was almost entirely because they refuse to allow new 737 designs to require a new type rating and therefore force weird aircraft/cockpit designs that would otherwise seem stupid.
Also, commercial aircraft aren't really certified based on how they handle stalls, spins and spirals. Swept wings already handle those situations very badly and therefore systems are designed to prevent the aircraft from entering those parts of its flight envelope.