because we spend SO much time without a helmet and armor on... seriously you cant see your face or skin color 99% of the game so why would they spend resource time and money on such a vain dress up barbi option? Dying armor and such is again sims / barbi options that just take up more texture memory.
Some people don't wear helmets in the game and for Larian boasting that "for those who want to customize out there, we've got a great character creator" there sure wasn't one. Also, no helmet completely covers your skin. If someone wanted to have a different skin colour, would that even change the game? They added two genders. Hell - according to you, there should have only been one right?
Unfortunately, you're mistaking "what Divinity 2 should have had" with a whole different game genre all together.
Everything suggested points to a sandbox game, where you can just fly around anywhere without any loading screens at all for no point other than being able to do so. D2 is not a sandbox game, and therefore does not have any sandbox elements that you say are "missing"
Companions wouldn't work with the story, either. You are MEANT to feel alone in the world, because you are THE LAST of your kind. Human companions and the like would not in any way shape or form be able to stand against the things you are going up against, and most probably wouldn't willingly join you, anyway.
Blocking, sure. I never understood why if I went sword/shield I had to rely on rolling around and did so just as easily as a ranger or assassin style character.
Ability to dye armor and facial customization? Again, that's for more open ended games and only really there so they can point and say, "see! We have all these things! Aren't we special?"
A sandbox game is where you don't have to follow the story and can do what you want. In Divinity II, if no area had loading screens and we could travel from the Battle Tower to the Orobas Fjords, would that change anything? Hell, we are a dragon but we can't fly from our Battle Tower?
Companions could have worked in the expansion though. Or you could have summoned the soldiers from your tower to help you fight. After all, the loading screen boasts we can make our own little army but we can't really.
Also, Dragon Age has facial customization and it's not an open world game and Mass Effect 2 gives you ability to dye armour and customize your face and again - it's not a open world game.