The stand sounds like the spring is going and the rubber pads on the feet are slick and sliding. It's normal but any tape that grabs a little, clear of coarse, and it won't slip as easy under the weight.

Your no sound issue is because the cube requires USB powered speakers especially for the cube or the turtle beach USB to mic and speaker dongle. The dongle requires no drivers and just works as with the apple speakers.

The lack of boot issue is common, when you change the video card it will likely happen again. Also after installing it it may not work with OS 9.