The initial concept for the game was certainly aligned to a more realistic approach than other action RPG's.
Combat is underpinned by real life physics, with various variables and metrics contributing to calculations of a weapons effectiveness against both armoured and unarmoured areas of an opponents body. In the most recent combat videos (for E3 and the like), we've been told that enemy statistics had been adjusted and scaled to an unrealistic degree in order to allow for testers to have longer interactions when trialing the various combat scenarios. This is not a true representation of the final iteration of combat. And it is expected that final game combat will be tense, and potentially quite fast paced. But again, the proof will be in the pudding.
Eating and sleeping or the lack thereof will impact Henry's abilities to function and ultimately his health. Assuming nothing has changed in that regard.
Can't comment on the inclusion of a hardcore mode. There has been random discussion about this, but nothing has been definitively confirmed that I'm aware of.
Player crafting has been completely stripped back. This was a decision the devs made last year as they decided it best to direct time, energy, and resources to other areas of focus / gameplay. There will continue to be alchemy and Henry will be able to sharpen weapons. He may also be able to repair armour.
No official release on whether or not NPC crafting will be available; as in having the option of an in-game smith crafting a unique piece for Henry to use, rather than him doing the crafting himself.