I'll start by saying the game looks incredible, very excited to try it out.
The time mechanic looks really unique and definitely provides a sense of immersion and pressure on the player which I think is really cool and I'll be interested to see how it works on release. It reminds me, in a way, of Vampyrs mechanic of drinking innocent blood - which was also really interesting and immersive.
I do think, however, there should be a setting somewhere that changes how much time you have or how much time is taken when doing certain tasks.
Perhaps increasing the time taken on missions and side objectives to offer more of a challenge during a play through or vice versa for those wanting a more laid back play through, or perhaps a toggle to allow for you to unlock skills without it costing time - I think there are about 90 skills/perks and to fully upgrade one takes 4 (ish) out of the 8 segments in a day.
I think this would provide, not only a bit of leniency and allow people who want to, to fully explore everything available without feeling too constrained for time, while also making successive playthroughs more interesting, unique and challenging for those who are interested in that - I definitely see myself fitting in both categories.
I'm curious to know what others think about this. Regardless, I look forward to playing the game at launch!