The keyboard feels horrible to me too. As I said elsewhere, especially in contrast to a Thinkpad, it’s unprecice and wobbly, feeling cheap. No decent pressure-point…. And yes, you know that you need backlight when you have none…
The position of the locks is easy to remember without looking… want to remove the card, then the switch has to be pulled in the direction you will pull the card. You added a card, than push the switch to the middle of the case.
But the fact, that your cards come out by pulling the cable, while being locked, seems to be an issue with the case (or the card) to me.
I like the plastic case too. It’s nice, feels well, etc. The only issue I see, the thermal design might be hit by the thermal resistance of the material. The CPU is getting very hot (I have a similar CPU in a Thinkpad with metal case, and you can’t touch the case in the region of the CPU when on load), and so so the fan has to do a lot of work. Might be the CPU isn’t the best choice, as of thermals, for a plastic case. I am interested how the case will look after some hundred hot hours…