I was suggesting reusing some of the sensor technology like they did with MGS. The MOC camera on the MGS was developed for the failed Mars Observer spacecraft (explaining the name Mars Observer Camera). I think most of the other instruments were MO derived, too. Using those sensors save tons of money and development time for MGS and contributed to the great scientific returns from the vehicle.

I suspect the same could apply to many of the sensors developed for the Beagle. Fix the vehicle bus problems and reuse the sensors, as well as some of the other subsystems that may be useful like perhaps the telemetry system. Just being able to reuse the mission software would save a lot of time and money. Not everything needs to be discarded.

I like your balsa wood heat shield idea. I've read that the first one or two of China's recoverable satellites used wooden heat shields, which were probably resin impregnated oak. It worked. The Russians have used retro rockets to brake parachutes for decades. I've seen footage of them airdropping tanks and other heavy equipment, with the braking rockets firing very shortly before impact. They appear to have a trigger wire hanging beneath the payload that fires the rockets when the wire contacts the ground. There are experiments underway to put small radars in cars to prevent rear-end collisions. There are also efforts to build single chip radars that are very light, and could be a natural for your application. With some clever design, it might be possible to redirect the radar's RF energy after landing to perform other experiments.