This is how I overcame my cable issues:
* I purchased an inexpensive 7/16" combination wrench and modified both ends to allow it to work on the cable adjustment lock nuts. I cut out a section of the box end so it would fit over the threads of the adjustment screw that is on the end of the chain and connects to the block to which the cables are attached. On the open end, I narrowed the wrench. This wrench now allows me to tighten the locknuts properly and as conveniently as is possible when working in a small space.
* I replaced a few of the white foam pieces that ensure the nuts on the cable ends do not turn. Note that they are molded with a hex cavity to engage with the nut, so the nut has to be rotated to a position that the hex cavity can fit over the nut. A few of mine where not engaged properly from the factory and were deformed. They had become rounded, not hex so I was not sure if they were still able to prevent the nut from rotating.
* On one side of the slide, the pulley mount was flexing the wall of the TT when it would hit the end of the slides travel. I replaced the small footprint wood spacer with a thinner (1/4") aluminum spacer that extends to the top tube in the wall and down to the top tube of the slide opening. By reducing the spacer thickness, the cables no longer rub on the inside of the vertical channel.
Photos of the modified wrench as well as the original factor pulley mount and the one I replaced it with are here:
http://www.keystonerv.org/forums/album.php?albumid=730
Since I made the modifications last spring I estimate the slide has been opened and closed approximately 30 times. The slack has gone from the recommended 1/2" to almost 3/4" during this time without any adjustments. So I am happy that cable adjustment will now only be part of my spring prep.