I think you have to be careful not to get too fixated on extremely improbable events, such as being unable to fly at V1. If that scenario is a big worry, then ETOPS is unthinkable! As others have pointed out, if you're happy to go from a wet/contaminated runway with the reduced margins involved (a reasonably well-used procedure), why should the far, far lower risk of needing a lot more runway than calculated be an issue?
For me, if an intersection departure saves time or taxi distance then I'll do it. As a consequence, I'm putting less energy into the brakes and tyres which is a safety plus. There are also many reasons why I'll take full length, such as contamination, MEL items, possible windshear, etc. I always have the option of not going if I don't like what I see, too.
IMHO, if you're worried about needing extra concrete post-V1, then you should spend a bit longer assessing the prevailing conditions, the serviceability of your aircraft and be *really* careful when you do your performance calculations. This is probably far better insurance than anything else.