1. Agree on not examining all-engine out scenario, but an opportunity to practice here and then would be more than welcome. As far as I know, at most outfits, it's limited only to initial type rating training...
The ditchings in transport category aircraft result mainly on luck and only if you are very lucky, the abilities come in play. Just add thick fog to Hudson scenario, or put that Gimli 767 at the limit of ETOPS range somewhere over the ocean at night. How would have that ended even with the best pilots in the world?
2. Of course not all engine failures on takeoff occur at V1. But it's the most tricky moment for it to fail, since you can't reject the takeoff and at the same time you are at very low speed and still on ground or at least in the rotation phase. You don't think we should waste the valuable sim time for engine failures at 5000ft with 250kts and AP already engaged?