Great work Louis! #5 is by far my favorite, followed by #2 and #8. The latter two being very Dieter Rams.
As you mentioned, the size of the holes/slots will be very important. To ‘transparent’, seeing too much of the inside, will likely not add the visual perception of the computer case. I’d advise you to test a couple of options once you get to the prototype phase. Looking forward to your next post!