For the issue with the HUD cable, I had a similar problem on my '92, and the cable wasn't broken but it was getting stuck/bent where it pushes through the cable sleeve. If I remember correctly, I removed the snap-on dash panel, then disconnected a clip (?) to gain access to the rear of the control lever, and at that point, the cause of the problem was obvious. In my situation, I only needed to lube the cable and reassemble. I can't comment on whether or not the cause of your problem will be the same as mine was, though.
Sorry, but I can't comment on the cluster/traction control question.
'99 Bonneville SLE, white, 112,000 miles
'02 Park Avenue Ultra, white diamond pearl, 88,000 miles