I have a pretty strong suspicion that Lance or Alberto, Boonen or Cavendish would be plenty competitive atop an International at 17-19# even if everyone else were riding their modern CF steeds. And DA 7900 is decidedly not antiquated nor unsafe. Most typical C&V components may be a different story, but even then unsafe is a bit of a stretch.
I'll readily confess that I like C&V bikes because that's what I fancy myself riding like I used to, back when I was a 20yo, full of energy and strong as a horse. Sure, it's a little silly now, but then again that's a pretty common affliction among fat old men
I saw your Vitus 979 on your website. Beautiful bike. Why, I might even like to buy one someday. But I have a feeling riding it at my present size might not be the wisest idea either

When I was a kid I DID test ride an early lugged CF Giant at around 220# or so - nothing scary happened, and the bike and I fairly sprouted wings and flew away. It was cool.
Tom