It’s perfectly fine to leave the keyboard attached while carrying, it was designed for that. As long as you don’t beat it against a table it should be fine.
None of the materials on the keyboard should be able scratch it. The most common thing that might scratch it is sand (knives and keys won’t scratch it), so just make sure you keep your briefcase clean.
I have a Surface 3 and a Lenovo Miix 700, neither of which have screen protectors on them and both of which have travelled with me in my briefcase all over the world.
The screens on these things do not scratch easily. You should have no problems closing it keyboard to screen and keeping it in your briefcase.
I purchased a very thin mouse pad/key board cover.
Even though I put the flex glass protector on my screen.
The pad keeps smudges off the screen and would also protect from the anti glare coating issues if I did not already have the glass laid on top of the screen.
There are other complaints like yours. It’s not your fault. It is crap design that let’s the keyboard rub against the screen. Suggest you put something soft between the screen and keyboard to prevent further damage…like bubble wrap or felt or thin foam.
I’m using a bubble wrap sac as a protecting case for the V and the microfiber cloth between the screen and the keyboard + cleaning the keyboard.
So the real winner is:
ME
My came as filthy crap … bended, dusty … that plastic make screen worse, plus someone wrote on this forum, that after removal - screen coming was damaged.