Early on HP regen is awesome skill to have as it saves you money and consumables, but I have been considering dropping it now that HP is 5+k making 10HP / ~5 seconds rather lol worthy. Also money and food for days in pockets so even that makes it even less worth for me at this point. Focus is very nice general skill because adrenaline increases sword and sign damage, and with all increased adrenaline generation you get nice amount of damage output early into combat.
In combat I use a lot dodge step with some Quen and Aard thrown in so I personally don't get much from skills that prevent adrenaline loses from being hit. I just aim for not getting hit :b
Also those red mutagens... it was like pulling teeth to get them. Blue and green drops like nobodies business, but reds? ffs...