Is there a real world safety advantage buying a new/modern fwd over an older 740? It would depend on the model and year of the vehicle. A newer Benz or Volvo? Yes. A newer Toyota/Honda/Nissan? Probably not.
As for the various safety features, I think they return differing real world results. I have never been a fan of anti-lock brakes. They don't reduce your stopping distances, just allow skid control in some situations, and have only found it to be really useful on the larger trucks. I can bring my old 240 to a stop damn fast with no abs. The older 240/740 Volvo's have returned some impressive real world safety results, with very low crash injury and death numbers .

Airbags, especially the first generation bags, are good for some, and not for others. The 1st gen bag in my 5'3", 100lb daughter's car has been disconnected as per recommendation by her grandfather, who designed and manufactured air bags. If that thing goes off with her driving, it breaks her neck.

My 6', 200 lb son, on the other hand, would do well by the bag in the '94 940 that he drives. It also has other safety features that I think are a real world advantage, SIPS and the seat belt pre-tensioners ,that are not even included on my wife's '03 Toyota.

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Gary Gilliam Sumerduck VA, '94 940 na Regina 170k '86 240 199k, 93 Camry 4cyl 5spd 245k