Does that mean this is the final look of the inventory/roster screen?
No, we will continue polishing it.
One also can see 18 slots for mercs. Does that mean there will be up to 12 mercs fighting and 6 will be in reserve, since it was said that one won’t be able to control more than 12 on a battlefield?
Will one be able to decide how much of your mercs have to fight or will always 12 mercs fight, if one has 12 at least?
And the tent slots are for camp followers; up to 9 one can have?
The upper 2 rows contain 12 mercs max. There are more than 12 slots so you have more freedom in setting up your formation. The two rows represent how your men will be deployed in battle (facing upwards).
The tents are for your reserve. You can switch your men around freely and fight with less than 12 if you want to.
We considered using some of the reserve slots for camp followers, but did not come up with a quick and satisfying solution how to implement this whole mechanic. We are still considering it though.
While some of the former temporary blunt injuries depicted bruises, the updated image shows only bone fractures.
Are those icons supposed to display the same degree of damage, where the only difference is their source? If so, I would say the blunt injury icons should display bruises rather than fractures, because in my understanding a fracture is more severe than a cut or a stab wound and takes longer to heal.
Basically you are right. I took some artistic liberty to paint more visually engaging icons. Bruises dont really make good icons :)