Well, it is hard to damage an LCD TV. They don't use phosphors like CRTs and Plasamas, so they aren't subject to burn-in. (Although if you abuse the hell out of them by running static images for days at a time, as in some commercial display functions, you can create a similar "image persistance"...
You need to go into the setup of both your TW cable box and your DVD player and change the "TV type" or "TV shape" from 4:3 to 16:9. The zoom modes should only be used to zoom non-anamorphic (hard-matted) letterboxed material on DVD or non-HD channels. Your set should automatically adjust...