re: Nosecone and parachute
Beagle 2.
About the airbags, the engineers were acutely aware of the problems and claimed to have solved them.
About the nosecome shape: the same was used for the ARD which was successful (ok, the Earth isn't Mars).
The nosecone angle is especially important (according to a friend who works at ESTEC) for the aerodynamic stability during entry. The lander is spinning and also the center of gravity matters. About the height of the parachute opening: There is an unstable regime for mach 1.8-2. Beagle 2 has a more stable areodynamic shape allowing for a lower altitude parachute opening.
There is no single way to skin a cat.
The parachute.
And here too.
We all hope it works!
Raoul